omni-us · Dec 16, 2020 · Dec 16, 2020 · Dec 16, 2020 · Dec 23, 2020 · Dec 23, 2020
diff --git a/.bumpversion.cfg b/.bumpversion.cfg
@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 3.1.0
+current_version = 3.2.1
 commit = True
 tag = True
 tag_name = v{new_version}

diff --git a/.sonarcloud.properties b/.sonarcloud.properties
@@ -1,2 +1,2 @@
 sonar.sources=jsonargparse
-sonar.projectVersion=3.1.0
+sonar.projectVersion=3.2.1
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
@@ -9,12 +9,36 @@ follow `Semantic Versioning <https://semver.org/>`_
 only be introduced in major versions with advance notice in the **Deprecated**
 section of releases.
 
-v3.1.0 (2020-12-09)
+v3.2.1 (2020-12-30)
 -------------------
 
 Added
 ^^^^^
+- Automatic Optional for arguments with default None #30.
+- CLI now supports running methods from classes.
+- Signature arguments can now be loaded from independent config files #32.
+- add_argument now supports enable_path for type based on jsonschema.
+- print_config can now be given as value skip_null to exclude null entries.
+
+Changed
+^^^^^^^
+- Improved description of parser used as standalone and for ActionParser #34.
+- Removed :code:`__cwd__` and top level :code:`__path__` that were not needed.
+
+Fixed
+^^^^^
+- ActionYesNo argument in help the type is now bool.
+- Correctly skip self in add_method_arguments for inherited methods.
+- Prevent failure of dump in cleanup_actions due to new _ActionConfigLoad.
+- Prevent failure in save_paths for dict with int keys.
+- Avoid duplicate config check failure message with subcommands.
+
 
+v3.1.0 (2020-12-09)
+-------------------
+
+Added
+^^^^^
 - Support for multiple levels of subcommands #29.
 - Default description of subcommands explaining use of --help.
 
@@ -24,7 +48,6 @@ v3.0.1 (2020-12-02)
 
 Fixed
 ^^^^^
-
 - add_class_arguments incorrectly added arguments from :code:`__call__` instead
   of :code:`__init__` for callable classes.
 
@@ -34,7 +57,6 @@ v3.0.0 (2020-12-01)
 
 Added
 ^^^^^
-
 - Functions to add arguments from classes, methods and functions.
 - CLI function that allows creating a line command line interface with a single
   line of code inspired by Fire.
@@ -44,20 +66,16 @@ Added
 - Parsers now include --print_config option to dump defaults.
 - Support argcomplete for tab completion of arguments.
 
-
 Changed
 ^^^^^^^
-
 - ArgumentParsers by default now use as error_handler the
   usage_and_exit_error_handler.
 - error_handler and formatter_class no longer accept as value a string.
 - Changed SimpleNamespace to Namespace to avoid unnecessary differences with
   argparse.
 
-
 Deprecated
 ^^^^^^^^^^
-
 - ActionOperators should no longer be used, the new alternative is
   restricted number types.
 

diff --git a/README.rst b/README.rst
@@ -125,24 +125,77 @@ Then in a shell you could run:
     $ python example.py Lucky --prize=1000
     Lucky won 1000€!
 
-:func:`.CLI` without arguments searches for functions defined in the same module
-and in the local context where :func:`.CLI` is called. If more than one function
-is found, then any of them can be executed via :ref:`sub-commands`, e.g.
-:code:`python example.py subcommand [arguments]`. Alternatively one or more
-functions can be given to :func:`.CLI` skipping the automatic search.
+:func:`.CLI` without arguments searches for functions and classes defined in the
+same module and in the local context where :func:`.CLI` is called. Giving a
+single or a list functions/classes as first argument to :func:`.CLI` skips the
+automatic search and only includes what is given.
+
+When :func:`.CLI` receives a single class, the first arguments are used to
+instantiate the class, then a class method name must be given (see
+:ref:`sub-commands`) and the remaining arguments are used to run the class
+method. An example would be:
+
+.. code-block:: python
+
+    from random import randint
+    from jsonargparse import CLI
+
+    class Main:
+        def __init__(
+            self,
+            max_prize: int = 100
+        ):
+            """
+            Args:
+                max_prize: Maximum prize that can be awarded.
+            """
+            self.max_prize = max_prize
+
+        def person(
+            self,
+            name: str
+        ):
+            """
+            Args:
+                name: Name of winner.
+            """
+            return f'{name} won {randint(0, self.max_prize)}€!'
+
+    if __name__ == '__main__':
+        print(CLI(Main))
+
+Then in a shell you could run:
+
+.. code-block:: bash
+
+    $ python example.py --max_prize=1000 person Lucky
+    Lucky won 632€!
+
+If more than one function is given to :func:`.CLI`, then any of them can be
+executed via :ref:`sub-commands` similar to the single class example above, e.g.
+:code:`python example.py function [arguments]` where :code:`function` is the
+name of the function to execute.
+
+If multiple classes or a mixture of functions and classes is given to
+:func:`.CLI`, to execute a method of a class, two levels of :ref:`sub-commands`
+are required. The first sub-command would be name of the class and the second
+the name of the method, i.e. :code:`python example.py class [init_arguments]
+method [arguments]`. For more details about the automatic adding of arguments
+from classes and functions and the use of configuration files refer to section
+:ref:`classes-methods-functions`.
 
 This simple way of usage is similar and inspired by `Fire
 <https://pypi.org/project/fire/>`__. However, there are fundamental differences.
 First, the purpose is not allowing to call any python object from the command
-line. It is only intended for running functions specifically written for this
-purpose. Second, the arguments of the functions are required to have type hints,
-and the values will be validated according to these. Third, the return values of
-the functions are not automatically printed. :func:`.CLI` returns its value and
-it is up to the developer to decide what to do with it. Finally, jsonargparse
-has many features designed to help in creating convenient argument parsers such
-as: :ref:`nested-namespaces`, :ref:`configuration-files`, arguments from
-:ref:`classes-methods-functions`, additional type hints (:ref:`parsing-paths`,
-:ref:`restricted-numbers`, :ref:`restricted-strings`) and much more.
+line. It is only intended for running functions and classes specifically written
+for this purpose. Second, the arguments are required to have type hints, and the
+values will be validated according to these. Third, the return values of the
+functions are not automatically printed. :func:`.CLI` returns its value and it
+is up to the developer to decide what to do with it. Finally, jsonargparse has
+many features designed to help in creating convenient argument parsers such as:
+:ref:`nested-namespaces`, :ref:`configuration-files`, additional type hints
+(:ref:`parsing-paths`, :ref:`restricted-numbers`, :ref:`restricted-strings`) and
+much more.
 
 The next section explains how to create an argument parser in a very low level
 argparse-style. However, as parsers get more complex, being able to define them
@@ -320,7 +373,10 @@ configuration content can also be provided.
 
 All parsers include a :code:`--print_config` option. This is useful particularly
 for command line tools with a large set of options to create an initial config
-file including all default values.
+file including all default values. This option by default all entries, including
+the ones with :code:`null` values. If the argument is given as
+:code:`--print_config=skip_null`, then the entries with :code:`null` values will
+not be included.
 
 The config file can also be provided as an environment variable as explained
 in section :ref:`environment-variables`. The configuration file environment
@@ -395,6 +451,27 @@ since the init has the :code:`**kwargs` argument, the keyword arguments from
 :code:`value` as a required float and :code:`flag` as an optional boolean with
 default value false.
 
+Instead of using :func:`namespace_to_dict` to convert the namespaces to a
+dictionary, the :class:`.ArgumentParser` object can be instantiated with
+:code:`parse_as_dict=True` to get directly a dictionary from the parsing
+methods.
+
+When parsing from a configuration file (see :ref:`configuration-files`) all the
+values can be given in a single config file. However, for convenience it is also
+possible that the values for each of the groups created by the calls to the add
+signature methods can be parsed from independent files. This means that for the
+example above there could be one general config file with contents:
+
+.. code-block:: yaml
+
+    myclass:
+      init: myclass.yaml
+      method: mymethod.yaml
+
+Then the files :code:`myclass.yaml` and :code:`mymethod.yaml` would only include
+the settings for each of the instantiation of the class and the call to the
+method respectively.
+
 A wide range of type hints are supported. For exact details go to section
 :ref:`type-hints`. Some notes about the support for automatic adding of
 arguments are:
@@ -940,8 +1017,11 @@ populate the leaf nodes of the inner parser. In the example above, if
 checked to populate :code:`inner.node.op1`.
 
 An important detail to note is that the parsers that are given to
-:class:`.ActionParser` are internally modified. So they should be instantiated
-exclusively for the :class:`.ActionParser` and not used standalone.
+:class:`.ActionParser` are internally modified. Therefore, to use the parser
+both as standalone and an inner node, it is necessary to implement a function
+that instantiates the parser. This function would be used in one place to get an
+instance of the parser for standalone parsing, and in some other place use the
+function to provide an instance of the parser to :class:`.ActionParser`.
 
 
 Tab completion

diff --git a/docs/.buildinfo b/docs/.buildinfo
@@ -1,4 +1,4 @@
 # Sphinx build info version 1
 # This file hashes the configuration used when building these files. When it is not found, a full rebuild will be done.
-config: 04ec28750e3cd287a0109fa160c8d588
+config: 878f0894dcf8f9c240b49109bd5b5150
 tags: 645f666f9bcd5a90fca523b33c5a78b7
diff --git a/docs/CHANGELOG.html b/docs/CHANGELOG.html
@@ -7,7 +7,7 @@
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-  <title>Changelog &mdash; jsonargparse 3.1.0 documentation</title>
+  <title>Changelog &mdash; jsonargparse 3.2.1 documentation</title>
 
 
 
@@ -59,7 +59,7 @@
 
 
               <div class="version">
-                3.1.0
+                3.2.1
               </div>
 
 
@@ -87,17 +87,23 @@
               <!-- Local TOC -->
               <div class="local-toc"><ul>
 <li><a class="reference internal" href="#">Changelog</a><ul>
-<li><a class="reference internal" href="#v3-1-0-2020-12-09">v3.1.0 (2020-12-09)</a><ul>
+<li><a class="reference internal" href="#v3-2-1-2020-12-30">v3.2.1 (2020-12-30)</a><ul>
 <li><a class="reference internal" href="#added">Added</a></li>
+<li><a class="reference internal" href="#changed">Changed</a></li>
+<li><a class="reference internal" href="#fixed">Fixed</a></li>
+</ul>
+</li>
+<li><a class="reference internal" href="#v3-1-0-2020-12-09">v3.1.0 (2020-12-09)</a><ul>
+<li><a class="reference internal" href="#id2">Added</a></li>
 </ul>
 </li>
 <li><a class="reference internal" href="#v3-0-1-2020-12-02">v3.0.1 (2020-12-02)</a><ul>
-<li><a class="reference internal" href="#fixed">Fixed</a></li>
+<li><a class="reference internal" href="#id3">Fixed</a></li>
 </ul>
 </li>
 <li><a class="reference internal" href="#v3-0-0-2020-12-01">v3.0.0 (2020-12-01)</a><ul>
-<li><a class="reference internal" href="#id2">Added</a></li>
-<li><a class="reference internal" href="#changed">Changed</a></li>
+<li><a class="reference internal" href="#id4">Added</a></li>
+<li><a class="reference internal" href="#id5">Changed</a></li>
 <li><a class="reference internal" href="#deprecated">Deprecated</a></li>
 </ul>
 </li>
@@ -176,20 +182,50 @@
 (<code class="docutils literal notranslate"><span class="pre">&lt;major&gt;.&lt;minor&gt;.&lt;patch&gt;</span></code>). Backward incompatible (breaking) changes will
 only be introduced in major versions with advance notice in the <strong>Deprecated</strong>
 section of releases.</p>
-<div class="section" id="v3-1-0-2020-12-09">
-<h2>v3.1.0 (2020-12-09)<a class="headerlink" href="#v3-1-0-2020-12-09" title="Permalink to this headline">¶</a></h2>
+<div class="section" id="v3-2-1-2020-12-30">
+<h2>v3.2.1 (2020-12-30)<a class="headerlink" href="#v3-2-1-2020-12-30" title="Permalink to this headline">¶</a></h2>
 <div class="section" id="added">
 <h3>Added<a class="headerlink" href="#added" title="Permalink to this headline">¶</a></h3>
 <ul class="simple">
+<li><p>Automatic Optional for arguments with default None #30.</p></li>
+<li><p>CLI now supports running methods from classes.</p></li>
+<li><p>Signature arguments can now be loaded from independent config files #32.</p></li>
+<li><p>add_argument now supports enable_path for type based on jsonschema.</p></li>
+<li><p>print_config can now be given as value skip_null to exclude null entries.</p></li>
+</ul>
+</div>
+<div class="section" id="changed">
+<h3>Changed<a class="headerlink" href="#changed" title="Permalink to this headline">¶</a></h3>
+<ul class="simple">
+<li><p>Improved description of parser used as standalone and for ActionParser #34.</p></li>
+<li><p>Removed <code class="code docutils literal notranslate"><span class="pre">__cwd__</span></code> and top level <code class="code docutils literal notranslate"><span class="pre">__path__</span></code> that were not needed.</p></li>
+</ul>
+</div>
+<div class="section" id="fixed">
+<h3>Fixed<a class="headerlink" href="#fixed" title="Permalink to this headline">¶</a></h3>
+<ul class="simple">
+<li><p>ActionYesNo argument in help the type is now bool.</p></li>
+<li><p>Correctly skip self in add_method_arguments for inherited methods.</p></li>
+<li><p>Prevent failure of dump in cleanup_actions due to new _ActionConfigLoad.</p></li>
+<li><p>Prevent failure in save_paths for dict with int keys.</p></li>
+<li><p>Avoid duplicate config check failure message with subcommands.</p></li>
+</ul>
+</div>
+</div>
+<div class="section" id="v3-1-0-2020-12-09">
+<h2>v3.1.0 (2020-12-09)<a class="headerlink" href="#v3-1-0-2020-12-09" title="Permalink to this headline">¶</a></h2>
+<div class="section" id="id2">
+<h3>Added<a class="headerlink" href="#id2" title="Permalink to this headline">¶</a></h3>
+<ul class="simple">
 <li><p>Support for multiple levels of subcommands #29.</p></li>
 <li><p>Default description of subcommands explaining use of –help.</p></li>
 </ul>
 </div>
 </div>
 <div class="section" id="v3-0-1-2020-12-02">
 <h2>v3.0.1 (2020-12-02)<a class="headerlink" href="#v3-0-1-2020-12-02" title="Permalink to this headline">¶</a></h2>
-<div class="section" id="fixed">
-<h3>Fixed<a class="headerlink" href="#fixed" title="Permalink to this headline">¶</a></h3>
+<div class="section" id="id3">
+<h3>Fixed<a class="headerlink" href="#id3" title="Permalink to this headline">¶</a></h3>
 <ul class="simple">
 <li><p>add_class_arguments incorrectly added arguments from <code class="code docutils literal notranslate"><span class="pre">__call__</span></code> instead
 of <code class="code docutils literal notranslate"><span class="pre">__init__</span></code> for callable classes.</p></li>
@@ -198,8 +234,8 @@ <h3>Fixed<a class="headerlink" href="#fixed" title="Permalink to this headline">
 </div>
 <div class="section" id="v3-0-0-2020-12-01">
 <h2>v3.0.0 (2020-12-01)<a class="headerlink" href="#v3-0-0-2020-12-01" title="Permalink to this headline">¶</a></h2>
-<div class="section" id="id2">
-<h3>Added<a class="headerlink" href="#id2" title="Permalink to this headline">¶</a></h3>
+<div class="section" id="id4">
+<h3>Added<a class="headerlink" href="#id4" title="Permalink to this headline">¶</a></h3>
 <ul class="simple">
 <li><p>Functions to add arguments from classes, methods and functions.</p></li>
 <li><p>CLI function that allows creating a line command line interface with a single
@@ -211,8 +247,8 @@ <h3>Added<a class="headerlink" href="#id2" title="Permalink to this headline">¶
 <li><p>Support argcomplete for tab completion of arguments.</p></li>
 </ul>
 </div>
-<div class="section" id="changed">
-<h3>Changed<a class="headerlink" href="#changed" title="Permalink to this headline">¶</a></h3>
+<div class="section" id="id5">
+<h3>Changed<a class="headerlink" href="#id5" title="Permalink to this headline">¶</a></h3>
 <ul class="simple">
 <li><p>ArgumentParsers by default now use as error_handler the
 usage_and_exit_error_handler.</p></li>

diff --git a/docs/_modules/index.html b/docs/_modules/index.html
@@ -7,7 +7,7 @@
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-  <title>Overview: module code &mdash; jsonargparse 3.1.0 documentation</title>
+  <title>Overview: module code &mdash; jsonargparse 3.2.1 documentation</title>
 
 
 
@@ -59,7 +59,7 @@
 
 
               <div class="version">
-                3.1.0
+                3.2.1
               </div>
 
 

diff --git a/docs/_modules/jsonargparse/actions.html b/docs/_modules/jsonargparse/actions.html
diff --git a/docs/_modules/jsonargparse/cli.html b/docs/_modules/jsonargparse/cli.html
diff --git a/docs/_modules/jsonargparse/core.html b/docs/_modules/jsonargparse/core.html
diff --git a/docs/_modules/jsonargparse/formatters.html b/docs/_modules/jsonargparse/formatters.html
@@ -7,7 +7,7 @@
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-  <title>jsonargparse.formatters &mdash; jsonargparse 3.1.0 documentation</title>
+  <title>jsonargparse.formatters &mdash; jsonargparse 3.2.1 documentation</title>
 
 
 
@@ -59,7 +59,7 @@
 
 
               <div class="version">
-                3.1.0
+                3.2.1
               </div>
 
 
@@ -155,7 +155,7 @@ <h1>Source code for jsonargparse.formatters</h1><div class="highlight"><pre>
 
 <span class="kn">from</span> <span class="nn">.util</span> <span class="k">import</span> <span class="n">_get_env_var</span>
 <span class="kn">from</span> <span class="nn">.typing</span> <span class="k">import</span> <span class="n">type_to_str</span>
-<span class="kn">from</span> <span class="nn">.actions</span> <span class="k">import</span> <span class="n">ActionParser</span><span class="p">,</span> <span class="n">ActionEnum</span><span class="p">,</span> <span class="n">ActionConfigFile</span>
+<span class="kn">from</span> <span class="nn">.actions</span> <span class="k">import</span> <span class="n">ActionParser</span><span class="p">,</span> <span class="n">ActionEnum</span><span class="p">,</span> <span class="n">ActionYesNo</span><span class="p">,</span> <span class="n">ActionConfigFile</span>
 <span class="kn">from</span> <span class="nn">.jsonschema</span> <span class="k">import</span> <span class="n">ActionJsonSchema</span>
 
 
@@ -228,7 +228,9 @@ <h1>Source code for jsonargparse.formatters</h1><div class="highlight"><pre>
 
     <span class="k">def</span> <span class="nf">_get_type_str</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">action</span><span class="p">):</span>
         <span class="n">type_str</span> <span class="o">=</span> <span class="kc">None</span>
-        <span class="k">if</span> <span class="n">action</span><span class="o">.</span><span class="n">type</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
+        <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">action</span><span class="p">,</span> <span class="n">ActionYesNo</span><span class="p">):</span>
+            <span class="n">type_str</span> <span class="o">=</span> <span class="s1">&#39;bool&#39;</span>
+        <span class="k">elif</span> <span class="n">action</span><span class="o">.</span><span class="n">type</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
             <span class="n">type_str</span> <span class="o">=</span> <span class="n">type_to_str</span><span class="p">(</span><span class="n">action</span><span class="o">.</span><span class="n">type</span><span class="p">)</span>
         <span class="k">elif</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">action</span><span class="p">,</span> <span class="n">ActionEnum</span><span class="p">):</span>
             <span class="n">type_str</span> <span class="o">=</span> <span class="n">type_to_str</span><span class="p">(</span><span class="n">action</span><span class="o">.</span><span class="n">_enum</span><span class="p">)</span>

diff --git a/docs/_modules/jsonargparse/jsonnet.html b/docs/_modules/jsonargparse/jsonnet.html
@@ -7,7 +7,7 @@
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-  <title>jsonargparse.jsonnet &mdash; jsonargparse 3.1.0 documentation</title>
+  <title>jsonargparse.jsonnet &mdash; jsonargparse 3.2.1 documentation</title>
 
 
 
@@ -59,7 +59,7 @@
 
 
               <div class="version">
-                3.1.0
+                3.2.1
               </div>
 
 
@@ -222,7 +222,7 @@ <h1>Source code for jsonargparse.jsonnet</h1><div class="highlight"><pre>
                     <span class="k">try</span><span class="p">:</span>
                         <span class="n">schema</span> <span class="o">=</span> <span class="n">yaml</span><span class="o">.</span><span class="n">safe_load</span><span class="p">(</span><span class="n">schema</span><span class="p">)</span>
                     <span class="k">except</span> <span class="p">(</span><span class="n">yamlParserError</span><span class="p">,</span> <span class="n">yamlScannerError</span><span class="p">)</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
-                        <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">&#39;Problems parsing schema :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+                        <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">&#39;Problems parsing schema :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
                 <span class="n">jsonvalidator</span><span class="o">.</span><span class="n">check_schema</span><span class="p">(</span><span class="n">schema</span><span class="p">)</span>
                 <span class="bp">self</span><span class="o">.</span><span class="n">_validator</span> <span class="o">=</span> <span class="n">ActionJsonSchema</span><span class="o">.</span><span class="n">_extend_jsonvalidator_with_default</span><span class="p">(</span><span class="n">jsonvalidator</span><span class="p">)(</span><span class="n">schema</span><span class="p">)</span>
             <span class="k">else</span><span class="p">:</span>
@@ -269,7 +269,7 @@ <h1>Source code for jsonargparse.jsonnet</h1><div class="highlight"><pre>
                 <span class="n">value</span><span class="p">[</span><span class="n">num</span><span class="p">]</span> <span class="o">=</span> <span class="n">val</span>
             <span class="k">except</span> <span class="p">(</span><span class="ne">TypeError</span><span class="p">,</span> <span class="ne">RuntimeError</span><span class="p">,</span> <span class="n">yamlParserError</span><span class="p">,</span> <span class="n">yamlScannerError</span><span class="p">,</span> <span class="n">jsonschemaValidationError</span><span class="p">)</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
                 <span class="n">elem</span> <span class="o">=</span> <span class="s1">&#39;&#39;</span> <span class="k">if</span> <span class="ow">not</span> <span class="n">islist</span> <span class="k">else</span> <span class="s1">&#39; element &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">num</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span>
-                <span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s1">&#39;Parser key &quot;&#39;</span><span class="o">+</span><span class="bp">self</span><span class="o">.</span><span class="n">dest</span><span class="o">+</span><span class="s1">&#39;&quot;&#39;</span><span class="o">+</span><span class="n">elem</span><span class="o">+</span><span class="s1">&#39;: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+                <span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s1">&#39;Parser key &quot;&#39;</span><span class="o">+</span><span class="bp">self</span><span class="o">.</span><span class="n">dest</span><span class="o">+</span><span class="s1">&#39;&quot;&#39;</span><span class="o">+</span><span class="n">elem</span><span class="o">+</span><span class="s1">&#39;: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
         <span class="k">return</span> <span class="n">value</span> <span class="k">if</span> <span class="n">islist</span> <span class="k">else</span> <span class="n">value</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
 
 
@@ -325,7 +325,7 @@ <h1>Source code for jsonargparse.jsonnet</h1><div class="highlight"><pre>
         <span class="k">try</span><span class="p">:</span>
             <span class="n">values</span> <span class="o">=</span> <span class="n">yaml</span><span class="o">.</span><span class="n">safe_load</span><span class="p">(</span><span class="n">_jsonnet</span><span class="o">.</span><span class="n">evaluate_snippet</span><span class="p">(</span><span class="n">fname</span><span class="p">,</span> <span class="n">snippet</span><span class="p">,</span> <span class="n">ext_vars</span><span class="o">=</span><span class="n">ext_vars</span><span class="p">,</span> <span class="n">ext_codes</span><span class="o">=</span><span class="n">ext_codes</span><span class="p">))</span>
         <span class="k">except</span> <span class="ne">RuntimeError</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
-            <span class="k">raise</span> <span class="n">ParserError</span><span class="p">(</span><span class="s1">&#39;Problems evaluating jsonnet &quot;&#39;</span><span class="o">+</span><span class="n">fname</span><span class="o">+</span><span class="s1">&#39;&quot; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+            <span class="k">raise</span> <span class="n">ParserError</span><span class="p">(</span><span class="s1">&#39;Problems evaluating jsonnet &quot;&#39;</span><span class="o">+</span><span class="n">fname</span><span class="o">+</span><span class="s1">&#39;&quot; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
         <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_validator</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
             <span class="bp">self</span><span class="o">.</span><span class="n">_validator</span><span class="o">.</span><span class="n">validate</span><span class="p">(</span><span class="n">values</span><span class="p">)</span>
         <span class="k">if</span> <span class="n">with_meta</span> <span class="ow">and</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">values</span><span class="p">,</span> <span class="nb">dict</span><span class="p">)</span> <span class="ow">and</span> <span class="n">fpath</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>

diff --git a/docs/_modules/jsonargparse/jsonschema.html b/docs/_modules/jsonargparse/jsonschema.html
@@ -7,7 +7,7 @@
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-  <title>jsonargparse.jsonschema &mdash; jsonargparse 3.1.0 documentation</title>
+  <title>jsonargparse.jsonschema &mdash; jsonargparse 3.2.1 documentation</title>
 
 
 
@@ -59,7 +59,7 @@
 
 
               <div class="version">
-                3.1.0
+                3.2.1
               </div>
 
 
@@ -168,6 +168,7 @@ <h1>Source code for jsonargparse.jsonschema</h1><div class="highlight"><pre>
     <span class="n">ParserError</span><span class="p">,</span>
     <span class="n">strip_meta</span><span class="p">,</span>
     <span class="n">import_object</span><span class="p">,</span>
+    <span class="n">_load_config</span><span class="p">,</span>
     <span class="n">_check_unknown_kwargs</span><span class="p">,</span>
     <span class="n">_issubclass</span><span class="p">,</span>
 <span class="p">)</span>
@@ -176,7 +177,6 @@ <h1>Source code for jsonargparse.jsonschema</h1><div class="highlight"><pre>
     <span class="n">jsonschemaValidationError</span><span class="p">,</span>
     <span class="n">jsonschema_support</span><span class="p">,</span>
     <span class="n">import_jsonschema</span><span class="p">,</span>
-    <span class="n">get_config_read_mode</span><span class="p">,</span>
     <span class="n">files_completer</span><span class="p">,</span>
     <span class="n">argcomplete_warn_redraw_prompt</span><span class="p">,</span>
 <span class="p">)</span>
@@ -240,7 +240,7 @@ <h1>Source code for jsonargparse.jsonschema</h1><div class="highlight"><pre>
                 <span class="k">try</span><span class="p">:</span>
                     <span class="n">schema</span> <span class="o">=</span> <span class="n">yaml</span><span class="o">.</span><span class="n">safe_load</span><span class="p">(</span><span class="n">schema</span><span class="p">)</span>
                 <span class="k">except</span> <span class="p">(</span><span class="n">yamlParserError</span><span class="p">,</span> <span class="n">yamlScannerError</span><span class="p">)</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
-                    <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">&#39;Problems parsing schema :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+                    <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">&#39;Problems parsing schema :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
             <span class="n">jsonvalidator</span><span class="o">.</span><span class="n">check_schema</span><span class="p">(</span><span class="n">schema</span><span class="p">)</span>
             <span class="bp">self</span><span class="o">.</span><span class="n">_validator</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_extend_jsonvalidator_with_default</span><span class="p">(</span><span class="n">jsonvalidator</span><span class="p">)(</span><span class="n">schema</span><span class="p">)</span>
             <span class="bp">self</span><span class="o">.</span><span class="n">_enable_path</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="s1">&#39;enable_path&#39;</span><span class="p">,</span> <span class="kc">True</span><span class="p">)</span>
@@ -286,18 +286,7 @@ <h1>Source code for jsonargparse.jsonschema</h1><div class="highlight"><pre>
             <span class="n">value</span> <span class="o">=</span> <span class="p">[</span><span class="n">value</span><span class="p">]</span>
         <span class="k">for</span> <span class="n">num</span><span class="p">,</span> <span class="n">val</span> <span class="ow">in</span> <span class="nb">enumerate</span><span class="p">(</span><span class="n">value</span><span class="p">):</span>
             <span class="k">try</span><span class="p">:</span>
-                <span class="n">fpath</span> <span class="o">=</span> <span class="kc">None</span>
-                <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">val</span><span class="p">,</span> <span class="nb">str</span><span class="p">)</span> <span class="ow">and</span> <span class="n">val</span><span class="o">.</span><span class="n">strip</span><span class="p">()</span> <span class="o">!=</span> <span class="s1">&#39;&#39;</span><span class="p">:</span>
-                    <span class="n">parsed_val</span> <span class="o">=</span> <span class="n">yaml</span><span class="o">.</span><span class="n">safe_load</span><span class="p">(</span><span class="n">val</span><span class="p">)</span>
-                    <span class="k">if</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">parsed_val</span><span class="p">,</span> <span class="nb">str</span><span class="p">):</span>
-                        <span class="n">val</span> <span class="o">=</span> <span class="n">parsed_val</span>
-                <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_enable_path</span> <span class="ow">and</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">val</span><span class="p">,</span> <span class="nb">str</span><span class="p">):</span>
-                    <span class="k">try</span><span class="p">:</span>
-                        <span class="n">fpath</span> <span class="o">=</span> <span class="n">Path</span><span class="p">(</span><span class="n">val</span><span class="p">,</span> <span class="n">mode</span><span class="o">=</span><span class="n">get_config_read_mode</span><span class="p">())</span>
-                    <span class="k">except</span> <span class="ne">TypeError</span><span class="p">:</span>
-                        <span class="k">pass</span>
-                    <span class="k">else</span><span class="p">:</span>
-                        <span class="n">val</span> <span class="o">=</span> <span class="n">yaml</span><span class="o">.</span><span class="n">safe_load</span><span class="p">(</span><span class="n">fpath</span><span class="o">.</span><span class="n">get_content</span><span class="p">())</span>
+                <span class="n">val</span><span class="p">,</span> <span class="n">fpath</span> <span class="o">=</span> <span class="n">_load_config</span><span class="p">(</span><span class="n">val</span><span class="p">,</span> <span class="n">enable_path</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_enable_path</span><span class="p">,</span> <span class="n">flat_namespace</span><span class="o">=</span><span class="kc">False</span><span class="p">)</span>
                 <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">val</span><span class="p">,</span> <span class="n">Namespace</span><span class="p">):</span>
                     <span class="n">val</span> <span class="o">=</span> <span class="n">namespace_to_dict</span><span class="p">(</span><span class="n">val</span><span class="p">)</span>
                 <span class="n">val</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_adapt_types</span><span class="p">(</span><span class="n">val</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_annotation</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_subschemas</span><span class="p">,</span> <span class="n">reverse</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
@@ -311,7 +300,7 @@ <h1>Source code for jsonargparse.jsonschema</h1><div class="highlight"><pre>
                 <span class="n">value</span><span class="p">[</span><span class="n">num</span><span class="p">]</span> <span class="o">=</span> <span class="n">val</span>
             <span class="k">except</span> <span class="p">(</span><span class="ne">TypeError</span><span class="p">,</span> <span class="n">yamlParserError</span><span class="p">,</span> <span class="n">yamlScannerError</span><span class="p">,</span> <span class="n">jsonschemaValidationError</span><span class="p">)</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
                 <span class="n">elem</span> <span class="o">=</span> <span class="s1">&#39;&#39;</span> <span class="k">if</span> <span class="ow">not</span> <span class="n">islist</span> <span class="k">else</span> <span class="s1">&#39; element &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">num</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span>
-                <span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s1">&#39;Parser key &quot;&#39;</span><span class="o">+</span><span class="bp">self</span><span class="o">.</span><span class="n">dest</span><span class="o">+</span><span class="s1">&#39;&quot;&#39;</span><span class="o">+</span><span class="n">elem</span><span class="o">+</span><span class="s1">&#39;: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+                <span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="s1">&#39;Parser key &quot;&#39;</span><span class="o">+</span><span class="bp">self</span><span class="o">.</span><span class="n">dest</span><span class="o">+</span><span class="s1">&#39;&quot;&#39;</span><span class="o">+</span><span class="n">elem</span><span class="o">+</span><span class="s1">&#39;: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
         <span class="k">return</span> <span class="n">value</span> <span class="k">if</span> <span class="n">islist</span> <span class="k">else</span> <span class="n">value</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
 
 
@@ -386,7 +375,7 @@ <h1>Source code for jsonargparse.jsonschema</h1><div class="highlight"><pre>
                             <span class="n">init_args</span> <span class="o">=</span> <span class="n">parser</span><span class="o">.</span><span class="n">instantiate_subclasses</span><span class="p">(</span><span class="n">val</span><span class="p">[</span><span class="s1">&#39;init_args&#39;</span><span class="p">])</span>
                             <span class="n">val</span> <span class="o">=</span> <span class="n">val_class</span><span class="p">(</span><span class="o">**</span><span class="n">init_args</span><span class="p">)</span>  <span class="c1"># pylint: disable=not-a-mapping</span>
                 <span class="k">except</span> <span class="p">(</span><span class="ne">ImportError</span><span class="p">,</span> <span class="n">ModuleNotFound</span><span class="p">,</span> <span class="ne">AttributeError</span><span class="p">,</span> <span class="ne">AssertionError</span><span class="p">,</span> <span class="n">ParserError</span><span class="p">)</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
-                    <span class="k">raise</span> <span class="n">ParserError</span><span class="p">(</span><span class="s1">&#39;Problem with given class_path &quot;&#39;</span><span class="o">+</span><span class="n">val</span><span class="p">[</span><span class="s1">&#39;class_path&#39;</span><span class="p">]</span><span class="o">+</span><span class="s1">&#39;&quot; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+                    <span class="k">raise</span> <span class="n">ParserError</span><span class="p">(</span><span class="s1">&#39;Problem with given class_path &quot;&#39;</span><span class="o">+</span><span class="n">val</span><span class="p">[</span><span class="s1">&#39;class_path&#39;</span><span class="p">]</span><span class="o">+</span><span class="s1">&#39;&quot; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
             <span class="k">return</span> <span class="n">val</span>
 
         <span class="k">elif</span> <span class="n">annotation</span><span class="o">.</span><span class="n">__origin__</span> <span class="o">==</span> <span class="n">Union</span><span class="p">:</span>

diff --git a/docs/_modules/jsonargparse/optionals.html b/docs/_modules/jsonargparse/optionals.html
@@ -7,7 +7,7 @@
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-  <title>jsonargparse.optionals &mdash; jsonargparse 3.1.0 documentation</title>
+  <title>jsonargparse.optionals &mdash; jsonargparse 3.2.1 documentation</title>
 
 
 
@@ -59,7 +59,7 @@
 
 
               <div class="version">
-                3.1.0
+                3.2.1
               </div>
 
 
@@ -199,55 +199,55 @@ <h1>Source code for jsonargparse.optionals</h1><div class="highlight"><pre>
         <span class="kn">from</span> <span class="nn">jsonschema</span> <span class="k">import</span> <span class="n">Draft7Validator</span> <span class="k">as</span> <span class="n">jsonvalidator</span>
         <span class="k">return</span> <span class="n">jsonschema</span><span class="p">,</span> <span class="n">jsonvalidator</span>
     <span class="k">except</span> <span class="p">(</span><span class="ne">ImportError</span><span class="p">,</span> <span class="n">ModuleNotFound</span><span class="p">)</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
-        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;jsonschema package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;jsonschema package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
 
 
 <span class="k">def</span> <span class="nf">import_jsonnet</span><span class="p">(</span><span class="n">importer</span><span class="p">):</span>
     <span class="k">try</span><span class="p">:</span>
         <span class="kn">import</span> <span class="nn">_jsonnet</span>
         <span class="k">return</span> <span class="n">_jsonnet</span>
     <span class="k">except</span> <span class="p">(</span><span class="ne">ImportError</span><span class="p">,</span> <span class="n">ModuleNotFound</span><span class="p">)</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
-        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;jsonnet package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;jsonnet package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
 
 
 <span class="k">def</span> <span class="nf">import_url_validator</span><span class="p">(</span><span class="n">importer</span><span class="p">):</span>
     <span class="k">try</span><span class="p">:</span>
         <span class="kn">from</span> <span class="nn">validators.url</span> <span class="k">import</span> <span class="n">url</span> <span class="k">as</span> <span class="n">url_validator</span>
         <span class="k">return</span> <span class="n">url_validator</span>
     <span class="k">except</span> <span class="p">(</span><span class="ne">ImportError</span><span class="p">,</span> <span class="n">ModuleNotFound</span><span class="p">)</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
-        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;validators package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;validators package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
 
 
 <span class="k">def</span> <span class="nf">import_requests</span><span class="p">(</span><span class="n">importer</span><span class="p">):</span>
     <span class="k">try</span><span class="p">:</span>
         <span class="kn">import</span> <span class="nn">requests</span>
         <span class="k">return</span> <span class="n">requests</span>
     <span class="k">except</span> <span class="p">(</span><span class="ne">ImportError</span><span class="p">,</span> <span class="n">ModuleNotFound</span><span class="p">)</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
-        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;requests package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;requests package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
 
 
 <span class="k">def</span> <span class="nf">import_docstring_parse</span><span class="p">(</span><span class="n">importer</span><span class="p">):</span>
     <span class="k">try</span><span class="p">:</span>
         <span class="kn">from</span> <span class="nn">docstring_parser</span> <span class="k">import</span> <span class="n">parse</span> <span class="k">as</span> <span class="n">docstring_parse</span>
         <span class="k">return</span> <span class="n">docstring_parse</span>
     <span class="k">except</span> <span class="p">(</span><span class="ne">ImportError</span><span class="p">,</span> <span class="n">ModuleNotFound</span><span class="p">)</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
-        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;docstring-parser package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;docstring-parser package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
 
 
 <span class="k">def</span> <span class="nf">import_argcomplete</span><span class="p">(</span><span class="n">importer</span><span class="p">):</span>
     <span class="k">try</span><span class="p">:</span>
         <span class="kn">import</span> <span class="nn">argcomplete</span>
         <span class="k">return</span> <span class="n">argcomplete</span>
     <span class="k">except</span> <span class="p">(</span><span class="ne">ImportError</span><span class="p">,</span> <span class="n">ModuleNotFound</span><span class="p">)</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
-        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;argcomplete package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;argcomplete package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
 
 
 <span class="k">def</span> <span class="nf">import_dataclasses</span><span class="p">(</span><span class="n">importer</span><span class="p">):</span>
     <span class="k">try</span><span class="p">:</span>
         <span class="kn">import</span> <span class="nn">dataclasses</span>
         <span class="k">return</span> <span class="n">dataclasses</span>
     <span class="k">except</span> <span class="p">(</span><span class="ne">ImportError</span><span class="p">,</span> <span class="n">ModuleNotFound</span><span class="p">)</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
-        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;dataclasses package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+        <span class="k">raise</span> <span class="ne">ImportError</span><span class="p">(</span><span class="s1">&#39;dataclasses package is required by &#39;</span><span class="o">+</span><span class="n">importer</span><span class="o">+</span><span class="s1">&#39; :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
 
 
 <div class="viewcode-block" id="set_url_support"><a class="viewcode-back" href="../../index.html#jsonargparse.optionals.set_url_support">[docs]</a><span class="k">def</span> <span class="nf">set_url_support</span><span class="p">(</span><span class="n">enabled</span><span class="p">:</span><span class="nb">bool</span><span class="p">):</span>

diff --git a/docs/_modules/jsonargparse/signatures.html b/docs/_modules/jsonargparse/signatures.html
@@ -7,7 +7,7 @@
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-  <title>jsonargparse.signatures &mdash; jsonargparse 3.1.0 documentation</title>
+  <title>jsonargparse.signatures &mdash; jsonargparse 3.2.1 documentation</title>
 
 
 
@@ -59,7 +59,7 @@
 
 
               <div class="version">
-                3.1.0
+                3.2.1
               </div>
 
 
@@ -155,7 +155,8 @@ <h1>Source code for jsonargparse.signatures</h1><div class="highlight"><pre>
 <span class="kn">from</span> <span class="nn">typing</span> <span class="k">import</span> <span class="n">Union</span><span class="p">,</span> <span class="n">Optional</span><span class="p">,</span> <span class="n">List</span><span class="p">,</span> <span class="n">Container</span><span class="p">,</span> <span class="n">Type</span><span class="p">,</span> <span class="n">Callable</span>
 
 <span class="kn">from</span> <span class="nn">.util</span> <span class="k">import</span> <span class="n">_issubclass</span>
-<span class="kn">from</span> <span class="nn">.actions</span> <span class="k">import</span> <span class="n">ActionEnum</span>
+<span class="kn">from</span> <span class="nn">.actions</span> <span class="k">import</span> <span class="n">ActionEnum</span><span class="p">,</span> <span class="n">_ActionConfigLoad</span>
+<span class="kn">from</span> <span class="nn">.typing</span> <span class="k">import</span> <span class="n">is_optional</span>
 <span class="kn">from</span> <span class="nn">.jsonschema</span> <span class="k">import</span> <span class="n">ActionJsonSchema</span>
 <span class="kn">from</span> <span class="nn">.optionals</span> <span class="k">import</span> <span class="n">docstring_parser_support</span><span class="p">,</span> <span class="n">import_docstring_parse</span><span class="p">,</span> <span class="n">dataclasses_support</span><span class="p">,</span> <span class="n">import_dataclasses</span>
 
@@ -242,9 +243,9 @@ <h1>Source code for jsonargparse.signatures</h1><div class="highlight"><pre>
         <span class="k">if</span> <span class="ow">not</span> <span class="n">inspect</span><span class="o">.</span><span class="n">isclass</span><span class="p">(</span><span class="n">theclass</span><span class="p">):</span>
             <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">&#39;Expected a class object.&#39;</span><span class="p">)</span>
         <span class="k">if</span> <span class="ow">not</span> <span class="nb">hasattr</span><span class="p">(</span><span class="n">theclass</span><span class="p">,</span> <span class="n">themethod</span><span class="p">)</span> <span class="ow">or</span> <span class="ow">not</span> <span class="n">callable</span><span class="p">(</span><span class="nb">getattr</span><span class="p">(</span><span class="n">theclass</span><span class="p">,</span> <span class="n">themethod</span><span class="p">)):</span>
-            <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">&#39;Expected the method to a callable member of the class.&#39;</span><span class="p">)</span>
+            <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">&#39;Expected the method to be a callable member of the class.&#39;</span><span class="p">)</span>
 
-        <span class="n">skip_first</span> <span class="o">=</span> <span class="kc">False</span> <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">theclass</span><span class="o">.</span><span class="vm">__dict__</span><span class="p">[</span><span class="n">themethod</span><span class="p">],</span> <span class="nb">staticmethod</span><span class="p">)</span> <span class="k">else</span> <span class="kc">True</span>
+        <span class="n">skip_first</span> <span class="o">=</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">inspect</span><span class="o">.</span><span class="n">getattr_static</span><span class="p">(</span><span class="n">theclass</span><span class="p">,</span> <span class="n">themethod</span><span class="p">),</span> <span class="nb">staticmethod</span><span class="p">)</span>
         <span class="n">themethod</span> <span class="o">=</span> <span class="nb">getattr</span><span class="p">(</span><span class="n">theclass</span><span class="p">,</span> <span class="n">themethod</span><span class="p">)</span>
 
         <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_add_signature_arguments</span><span class="p">([</span><span class="n">themethod</span><span class="p">],</span>
@@ -363,6 +364,8 @@ <h1>Source code for jsonargparse.signatures</h1><div class="highlight"><pre>
                 <span class="n">doc_group</span> <span class="o">=</span> <span class="nb">str</span><span class="p">(</span><span class="n">objects</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span>
             <span class="n">name</span> <span class="o">=</span> <span class="n">objects</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="vm">__name__</span> <span class="k">if</span> <span class="n">nested_key</span> <span class="ow">is</span> <span class="kc">None</span> <span class="k">else</span> <span class="n">nested_key</span>
             <span class="n">group</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">add_argument_group</span><span class="p">(</span><span class="n">doc_group</span><span class="p">,</span> <span class="n">name</span><span class="o">=</span><span class="n">name</span><span class="p">)</span>  <span class="c1"># type: ignore</span>
+            <span class="k">if</span> <span class="n">nested_key</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
+                <span class="n">group</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">&#39;--&#39;</span><span class="o">+</span><span class="n">nested_key</span><span class="p">,</span> <span class="n">action</span><span class="o">=</span><span class="n">_ActionConfigLoad</span><span class="p">)</span>  <span class="c1"># type: ignore</span>
 
         <span class="c1">## Add objects arguments ##</span>
         <span class="n">added_args</span> <span class="o">=</span> <span class="nb">set</span><span class="p">()</span>
@@ -397,6 +400,8 @@ <h1>Source code for jsonargparse.signatures</h1><div class="highlight"><pre>
                 <span class="n">kwargs</span> <span class="o">=</span> <span class="p">{</span><span class="s1">&#39;help&#39;</span><span class="p">:</span> <span class="n">doc_params</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="n">name</span><span class="p">)}</span>
                 <span class="k">if</span> <span class="ow">not</span> <span class="n">is_required</span><span class="p">:</span>
                     <span class="n">kwargs</span><span class="p">[</span><span class="s1">&#39;default&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="n">default</span>
+                    <span class="k">if</span> <span class="n">default</span> <span class="ow">is</span> <span class="kc">None</span> <span class="ow">and</span> <span class="ow">not</span> <span class="n">is_optional</span><span class="p">(</span><span class="n">annotation</span><span class="p">,</span> <span class="nb">object</span><span class="p">):</span>
+                        <span class="n">annotation</span> <span class="o">=</span> <span class="n">Optional</span><span class="p">[</span><span class="n">annotation</span><span class="p">]</span>
                 <span class="k">elif</span> <span class="ow">not</span> <span class="n">as_positional</span><span class="p">:</span>
                     <span class="n">kwargs</span><span class="p">[</span><span class="s1">&#39;required&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="kc">True</span>
                 <span class="k">if</span> <span class="n">annotation</span> <span class="ow">in</span> <span class="p">{</span><span class="nb">str</span><span class="p">,</span> <span class="nb">int</span><span class="p">,</span> <span class="nb">float</span><span class="p">,</span> <span class="nb">bool</span><span class="p">}</span> <span class="ow">or</span> \

diff --git a/docs/_modules/jsonargparse/typing.html b/docs/_modules/jsonargparse/typing.html
@@ -7,7 +7,7 @@
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-  <title>jsonargparse.typing &mdash; jsonargparse 3.1.0 documentation</title>
+  <title>jsonargparse.typing &mdash; jsonargparse 3.2.1 documentation</title>
 
 
 
@@ -59,7 +59,7 @@
 
 
               <div class="version">
-                3.1.0
+                3.2.1
               </div>
 
 

diff --git a/docs/_modules/jsonargparse/util.html b/docs/_modules/jsonargparse/util.html
@@ -7,7 +7,7 @@
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-  <title>jsonargparse.util &mdash; jsonargparse 3.1.0 documentation</title>
+  <title>jsonargparse.util &mdash; jsonargparse 3.2.1 documentation</title>
 
 
 
@@ -59,7 +59,7 @@
 
 
               <div class="version">
-                3.1.0
+                3.2.1
               </div>
 
 
@@ -154,6 +154,7 @@ <h1>Source code for jsonargparse.util</h1><div class="highlight"><pre>
 <span class="kn">import</span> <span class="nn">re</span>
 <span class="kn">import</span> <span class="nn">sys</span>
 <span class="kn">import</span> <span class="nn">stat</span>
+<span class="kn">import</span> <span class="nn">yaml</span>
 <span class="kn">import</span> <span class="nn">inspect</span>
 <span class="kn">import</span> <span class="nn">logging</span>
 <span class="kn">from</span> <span class="nn">copy</span> <span class="k">import</span> <span class="n">deepcopy</span>
@@ -163,7 +164,13 @@ <h1>Source code for jsonargparse.util</h1><div class="highlight"><pre>
 <span class="kn">from</span> <span class="nn">yaml.parser</span> <span class="k">import</span> <span class="n">ParserError</span> <span class="k">as</span> <span class="n">yamlParserError</span>
 <span class="kn">from</span> <span class="nn">yaml.scanner</span> <span class="k">import</span> <span class="n">ScannerError</span> <span class="k">as</span> <span class="n">yamlScannerError</span>
 
-<span class="kn">from</span> <span class="nn">.optionals</span> <span class="k">import</span> <span class="n">ModuleNotFound</span><span class="p">,</span> <span class="n">url_support</span><span class="p">,</span> <span class="n">import_requests</span><span class="p">,</span> <span class="n">import_url_validator</span>
+<span class="kn">from</span> <span class="nn">.optionals</span> <span class="k">import</span> <span class="p">(</span>
+    <span class="n">ModuleNotFound</span><span class="p">,</span>
+    <span class="n">url_support</span><span class="p">,</span>
+    <span class="n">import_requests</span><span class="p">,</span>
+    <span class="n">import_url_validator</span><span class="p">,</span>
+    <span class="n">get_config_read_mode</span><span class="p">,</span>
+<span class="p">)</span>
 
 
 <span class="n">__all__</span> <span class="o">=</span> <span class="p">[</span>
@@ -182,14 +189,38 @@ <h1>Source code for jsonargparse.util</h1><div class="highlight"><pre>
 <span class="n">null_logger</span> <span class="o">=</span> <span class="n">logging</span><span class="o">.</span><span class="n">Logger</span><span class="p">(</span><span class="s1">&#39;jsonargparse_null_logger&#39;</span><span class="p">)</span>
 <span class="n">null_logger</span><span class="o">.</span><span class="n">addHandler</span><span class="p">(</span><span class="n">logging</span><span class="o">.</span><span class="n">NullHandler</span><span class="p">())</span>
 
-<span class="n">meta_keys</span> <span class="o">=</span> <span class="p">{</span><span class="s1">&#39;__cwd__&#39;</span><span class="p">,</span> <span class="s1">&#39;__path__&#39;</span><span class="p">,</span> <span class="s1">&#39;__default_config__&#39;</span><span class="p">}</span>
+<span class="n">meta_keys</span> <span class="o">=</span> <span class="p">{</span><span class="s1">&#39;__path__&#39;</span><span class="p">,</span> <span class="s1">&#39;__default_config__&#39;</span><span class="p">}</span>
 
 
 <div class="viewcode-block" id="ParserError"><a class="viewcode-back" href="../../index.html#jsonargparse.util.ParserError">[docs]</a><span class="k">class</span> <span class="nc">ParserError</span><span class="p">(</span><span class="ne">Exception</span><span class="p">):</span>
     <span class="sd">&quot;&quot;&quot;Error raised when parsing a value fails.&quot;&quot;&quot;</span>
     <span class="k">pass</span></div>
 
 
+<span class="k">def</span> <span class="nf">_load_config</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="n">enable_path</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">flat_namespace</span><span class="o">=</span><span class="kc">True</span><span class="p">):</span>
+    <span class="sd">&quot;&quot;&quot;Parses yaml config in a string or a path&quot;&quot;&quot;</span>
+    <span class="n">cfg_path</span> <span class="o">=</span> <span class="kc">None</span>
+    <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="nb">str</span><span class="p">)</span> <span class="ow">and</span> <span class="n">value</span><span class="o">.</span><span class="n">strip</span><span class="p">()</span> <span class="o">!=</span> <span class="s1">&#39;&#39;</span><span class="p">:</span>
+        <span class="n">parsed_val</span> <span class="o">=</span> <span class="n">yaml</span><span class="o">.</span><span class="n">safe_load</span><span class="p">(</span><span class="n">value</span><span class="p">)</span>
+        <span class="k">if</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">parsed_val</span><span class="p">,</span> <span class="nb">str</span><span class="p">):</span>
+            <span class="n">value</span> <span class="o">=</span> <span class="n">parsed_val</span>
+    <span class="k">if</span> <span class="n">enable_path</span> <span class="ow">and</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="nb">str</span><span class="p">):</span>
+        <span class="k">try</span><span class="p">:</span>
+            <span class="n">cfg_path</span> <span class="o">=</span> <span class="n">Path</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="n">mode</span><span class="o">=</span><span class="n">get_config_read_mode</span><span class="p">())</span>
+        <span class="k">except</span> <span class="ne">TypeError</span><span class="p">:</span>
+            <span class="k">pass</span>
+        <span class="k">else</span><span class="p">:</span>
+            <span class="n">value</span> <span class="o">=</span> <span class="n">yaml</span><span class="o">.</span><span class="n">safe_load</span><span class="p">(</span><span class="n">cfg_path</span><span class="o">.</span><span class="n">get_content</span><span class="p">())</span>
+
+    <span class="k">if</span> <span class="n">flat_namespace</span><span class="p">:</span>
+        <span class="n">value</span> <span class="o">=</span> <span class="n">_dict_to_flat_namespace</span><span class="p">(</span><span class="n">value</span><span class="p">)</span>
+        <span class="k">if</span> <span class="n">cfg_path</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
+            <span class="nb">setattr</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="s1">&#39;__path__&#39;</span><span class="p">,</span> <span class="n">cfg_path</span><span class="p">)</span>
+        <span class="k">return</span> <span class="n">value</span>
+
+    <span class="k">return</span> <span class="n">value</span><span class="p">,</span> <span class="n">cfg_path</span>
+
+
 <span class="k">def</span> <span class="nf">_get_key_value</span><span class="p">(</span><span class="n">cfg</span><span class="p">,</span> <span class="n">key</span><span class="p">,</span> <span class="n">parent</span><span class="o">=</span><span class="kc">False</span><span class="p">):</span>
     <span class="sd">&quot;&quot;&quot;Gets the value for a given key in a config object (dict or argparse.Namespace).&quot;&quot;&quot;</span>
     <span class="k">def</span> <span class="nf">key_in_cfg</span><span class="p">(</span><span class="n">cfg</span><span class="p">,</span> <span class="n">key</span><span class="p">):</span>
@@ -460,7 +491,7 @@ <h1>Source code for jsonargparse.util</h1><div class="highlight"><pre>
                 <span class="k">try</span><span class="p">:</span>
                     <span class="n">requests</span><span class="o">.</span><span class="n">head</span><span class="p">(</span><span class="n">abs_path</span><span class="p">)</span><span class="o">.</span><span class="n">raise_for_status</span><span class="p">()</span>
                 <span class="k">except</span> <span class="n">requests</span><span class="o">.</span><span class="n">HTTPError</span> <span class="k">as</span> <span class="n">ex</span><span class="p">:</span>
-                    <span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="n">abs_path</span><span class="o">+</span><span class="s1">&#39; HEAD not accessible :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span>
+                    <span class="k">raise</span> <span class="ne">TypeError</span><span class="p">(</span><span class="n">abs_path</span><span class="o">+</span><span class="s1">&#39; HEAD not accessible :: &#39;</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">ex</span><span class="p">))</span> <span class="kn">from</span> <span class="nn">ex</span>
         <span class="k">elif</span> <span class="ow">not</span> <span class="n">skip_check</span><span class="p">:</span>
             <span class="n">ptype</span> <span class="o">=</span> <span class="s1">&#39;Directory&#39;</span> <span class="k">if</span> <span class="s1">&#39;d&#39;</span> <span class="ow">in</span> <span class="n">mode</span> <span class="k">else</span> <span class="s1">&#39;File&#39;</span>
             <span class="k">if</span> <span class="s1">&#39;c&#39;</span> <span class="ow">in</span> <span class="n">mode</span><span class="p">:</span>

diff --git a/docs/_sources/CHANGELOG.rst.txt b/docs/_sources/CHANGELOG.rst.txt
@@ -9,12 +9,36 @@ follow `Semantic Versioning <https://semver.org/>`_
 only be introduced in major versions with advance notice in the **Deprecated**
 section of releases.
 
-v3.1.0 (2020-12-09)
+v3.2.1 (2020-12-30)
 -------------------
 
 Added
 ^^^^^
+- Automatic Optional for arguments with default None #30.
+- CLI now supports running methods from classes.
+- Signature arguments can now be loaded from independent config files #32.
+- add_argument now supports enable_path for type based on jsonschema.
+- print_config can now be given as value skip_null to exclude null entries.
+
+Changed
+^^^^^^^
+- Improved description of parser used as standalone and for ActionParser #34.
+- Removed :code:`__cwd__` and top level :code:`__path__` that were not needed.
+
+Fixed
+^^^^^
+- ActionYesNo argument in help the type is now bool.
+- Correctly skip self in add_method_arguments for inherited methods.
+- Prevent failure of dump in cleanup_actions due to new _ActionConfigLoad.
+- Prevent failure in save_paths for dict with int keys.
+- Avoid duplicate config check failure message with subcommands.
+
 
+v3.1.0 (2020-12-09)
+-------------------
+
+Added
+^^^^^
 - Support for multiple levels of subcommands #29.
 - Default description of subcommands explaining use of --help.
 
@@ -24,7 +48,6 @@ v3.0.1 (2020-12-02)
 
 Fixed
 ^^^^^
-
 - add_class_arguments incorrectly added arguments from :code:`__call__` instead
   of :code:`__init__` for callable classes.
 
@@ -34,7 +57,6 @@ v3.0.0 (2020-12-01)
 
 Added
 ^^^^^
-
 - Functions to add arguments from classes, methods and functions.
 - CLI function that allows creating a line command line interface with a single
   line of code inspired by Fire.
@@ -44,20 +66,16 @@ Added
 - Parsers now include --print_config option to dump defaults.
 - Support argcomplete for tab completion of arguments.
 
-
 Changed
 ^^^^^^^
-
 - ArgumentParsers by default now use as error_handler the
   usage_and_exit_error_handler.
 - error_handler and formatter_class no longer accept as value a string.
 - Changed SimpleNamespace to Namespace to avoid unnecessary differences with
   argparse.
 
-
 Deprecated
 ^^^^^^^^^^
-
 - ActionOperators should no longer be used, the new alternative is
   restricted number types.
 

diff --git a/docs/_static/documentation_options.js b/docs/_static/documentation_options.js
@@ -1,6 +1,6 @@
 var DOCUMENTATION_OPTIONS = {
     URL_ROOT: document.getElementById("documentation_options").getAttribute('data-url_root'),
-    VERSION: '3.1.0',
+    VERSION: '3.2.1',
     LANGUAGE: 'None',
     COLLAPSE_INDEX: false,
     BUILDER: 'html',

diff --git a/docs/genindex.html b/docs/genindex.html
@@ -7,7 +7,7 @@
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-  <title>Index &mdash; jsonargparse 3.1.0 documentation</title>
+  <title>Index &mdash; jsonargparse 3.2.1 documentation</title>
 
 
 
@@ -59,7 +59,7 @@
 
 
               <div class="version">
-                3.1.0
+                3.2.1
               </div>
 
 

diff --git a/docs/index.html b/docs/index.html
diff --git a/docs/objects.inv b/docs/objects.inv
diff --git a/docs/py-modindex.html b/docs/py-modindex.html
@@ -7,7 +7,7 @@
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-  <title>Python Module Index &mdash; jsonargparse 3.1.0 documentation</title>
+  <title>Python Module Index &mdash; jsonargparse 3.2.1 documentation</title>
 
 
 
@@ -62,7 +62,7 @@
 
 
               <div class="version">
-                3.1.0
+                3.2.1
               </div>
 
 

diff --git a/docs/search.html b/docs/search.html
@@ -7,7 +7,7 @@
 
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
 
-  <title>Search &mdash; jsonargparse 3.1.0 documentation</title>
+  <title>Search &mdash; jsonargparse 3.2.1 documentation</title>
 
 
 
@@ -61,7 +61,7 @@
 
 
               <div class="version">
-                3.1.0
+                3.2.1
               </div>
 
 

diff --git a/docs/searchindex.js b/docs/searchindex.js
diff --git a/jsonargparse/__init__.py b/jsonargparse/__init__.py
@@ -20,4 +20,4 @@
 )
 
 
-__version__ = '3.1.0'
+__version__ = '3.2.1'
diff --git a/jsonargparse/actions.py b/jsonargparse/actions.py
@@ -17,6 +17,7 @@
     namespace_to_dict,
     dict_to_namespace,
     Path,
+    _load_config,
     _flat_namespace_to_dict,
     _dict_to_flat_namespace,
     _check_unknown_kwargs,
@@ -103,32 +104,54 @@ def _apply_config(parser, namespace, dest, value):
                 cfg_path = None
                 cfg_file = parser.parse_string(value, env=False, defaults=False, _skip_check=True)
             except (TypeError, yamlParserError, yamlScannerError) as ex_str:
-                raise TypeError('Parser key "'+dest+'": '+str(ex_str))
+                raise TypeError('Parser key "'+dest+'": '+str(ex_str)) from ex_str
         else:
             cfg_file = parser.parse_path(value, env=False, defaults=False, _skip_check=True)
         cfg_file = _dict_to_flat_namespace(namespace_to_dict(cfg_file))
         getattr(namespace, dest).append(cfg_path)
         for key, val in vars(cfg_file).items():
-            if key == '__cwd__' and hasattr(namespace, '__cwd__'):
-                setattr(namespace, key, getattr(namespace, key)+val)
-            else:
-                setattr(namespace, key, val)
+            setattr(namespace, key, val)
 
 
 class _ActionPrintConfig(Action):
     def __init__(self,
                  option_strings,
                  dest=SUPPRESS,
-                 default=SUPPRESS,
-                 help='print configuration and exit'):
+                 default=SUPPRESS):
         super().__init__(option_strings=option_strings,
                          dest=dest,
                          default=default,
-                         nargs=0,
-                         help=help)
+                         nargs='?',
+                         metavar='skip_null',
+                         help='Print configuration and exit.')
+
+    def __call__(self, parser, namespace, value, option_string=None):
+        kwargs = {'skip_none': False}
+        if value is not None and 'skip_null' in value:
+            kwargs['skip_none'] = True
+        parser._print_config = kwargs
+
+
+class _ActionConfigLoad(Action):
+
+    def __init__(self, **kwargs):
+        kwargs['help'] = SUPPRESS
+        kwargs['default'] = SUPPRESS
+        super().__init__(**kwargs)
+
+    def __call__(self, parser, namespace, value, option_string=None):
+        cfg_file = self._load_config(value)
+        for key, val in vars(cfg_file).items():
+            setattr(namespace, self.dest+'.'+key, val)
 
-    def __call__(self, parser, *args, **kwargs):
-        parser._print_config = True
+    def _load_config(self, value):
+        try:
+            return _load_config(value)
+        except (TypeError, yamlParserError, yamlScannerError) as ex:
+            raise TypeError('Parser key "'+self.dest+'": '+str(ex)) from ex
+
+    def _check_type(self, value, cfg=None):
+        return self._load_config(value)
 
 
 class ActionYesNo(Action):
@@ -341,7 +364,7 @@ def _check_type(self, value, cfg=None):
             if fpath is not None:
                 value.__path__ = fpath
         except KeyError as ex:
-            raise type(ex)(re.sub('^Parser key ([^:]+):', 'Parser key '+self.dest+'.\\1: ', str(ex)))
+            raise type(ex)(re.sub('^Parser key ([^:]+):', 'Parser key '+self.dest+'.\\1: ', str(ex))) from ex
         return value
 
     @staticmethod
@@ -535,7 +558,7 @@ def _check_type(self, value, cfg=None, islist=None):
                     val = Path(val, mode=self._mode, skip_check=self._skip_check)
                 value[num] = val
         except TypeError as ex:
-            raise TypeError('Parser key "'+self.dest+'": '+str(ex))
+            raise TypeError('Parser key "'+self.dest+'": '+str(ex)) from ex
         return value if islist else value[0]
 
 
@@ -598,7 +621,7 @@ def _check_type(self, value, cfg=None):
                     with sys.stdin if path_list_file == '-' else open(path_list_file, 'r') as f:
                         path_list = [x.strip() for x in f.readlines()]
                 except FileNotFoundError as ex:
-                    raise TypeError('Problems reading path list: '+path_list_file+' :: '+str(ex))
+                    raise TypeError('Problems reading path list: '+path_list_file+' :: '+str(ex)) from ex
                 cwd = os.getcwd()
                 if self._rel == 'list' and path_list_file != '-':
                     os.chdir(os.path.abspath(os.path.join(path_list_file, os.pardir)))
@@ -607,7 +630,7 @@ def _check_type(self, value, cfg=None):
                         try:
                             path_list[num] = Path(val, mode=self._mode)
                         except TypeError as ex:
-                            raise TypeError('Path number '+str(num+1)+' in list '+path_list_file+', '+str(ex))
+                            raise TypeError('Path number '+str(num+1)+' in list '+path_list_file+', '+str(ex)) from ex
                 finally:
                     os.chdir(cwd)
                 value += path_list

diff --git a/jsonargparse/cli.py b/jsonargparse/cli.py
@@ -1,7 +1,7 @@
 """Simple creation of command line interfaces."""
 
 import inspect
-from typing import Union, List, Callable
+from typing import Union, List, Callable, Type
 from .core import ArgumentParser
 from .actions import ActionConfigFile
 
@@ -10,63 +10,89 @@
 
 
 def CLI(
-    functions: Union[Callable, List[Callable]] = None,
+    components: Union[Callable, Type, List[Union[Callable, Type]]] = None,
     args: List[str] = None,
     config_help: str = 'Path to a configuration file in json or yaml format.',
     as_positional: bool = True,
     **kwargs
 ):
     """Function for simple creation of command line interfaces.
 
-    Creates an argument parser from one or more functions, parses arguments and
-    runs one of the functions depending on what was parsed. If the functions
-    argument is not given, then the functions will be all the locals in the
-    context and defined in the same module as from where CLI is called.
+    Creates an argument parser from one or more functions/classes, parses
+    arguments and runs one of the functions or class methods depending on what
+    was parsed. If the components argument is not given, then the components
+    will be all the locals in the context and defined in the same module as from
+    where CLI is called.
 
     Args:
-        functions: One or more functions to include in the command line interface.
+        components: One or more functions/classes to include in the command line interface.
         args: List of arguments to parse or None to use sys.argv.
         config_help: Help string for config file option in help.
         as_positional: Whether to add required parameters as positional arguments.
         **kwargs: Used to instantiate :class:`.ArgumentParser`.
 
     Returns:
-        The value returned by the executed function.
+        The value returned by the executed function or class method.
     """
     caller = inspect.stack()[1][0]
     if 'description' not in kwargs:
         kwargs['description'] = caller.f_globals['__doc__']
 
-    if functions is None:
+    if components is None:
         module = inspect.getmodule(caller).__name__  # type: ignore
-        functions = [
+        components = [
             v for v in caller.f_locals.values()
-            if inspect.isfunction(v) and inspect.getmodule(v).__name__ == module  # type: ignore
+            if (inspect.isfunction(v) or inspect.isclass(v)) and inspect.getmodule(v).__name__ == module  # type: ignore
         ]
-        if len(functions) == 0:
-            raise ValueError('Either functions argument must be given or there must be at least one '
-                             'function among the locals in the context where CLI is called.')
+        if len(components) == 0:
+            raise ValueError('Either components argument must be given or there must be at least one '
+                             'function or class among the locals in the context where CLI is called.')
 
-    elif not isinstance(functions, list):
-        functions = [functions]
+    elif not isinstance(components, list):
+        components = [components]
 
     parser = ArgumentParser(parse_as_dict=True, default_meta=False, **kwargs)
     parser.add_argument('--config', action=ActionConfigFile, help=config_help)
 
-    if len(functions) == 1:
-        parser.add_function_arguments(functions[0], as_positional=as_positional)
+    if len(components) == 1:
+        component = components[0]
+        _add_component_to_parser(component, parser, as_positional)
         cfg = parser.parse_args(args)
-        del cfg['config']  # pylint: disable=unsupported-delete-operation
-        return functions[0](**cfg)  # type: ignore  # pylint: disable=not-a-mapping
+        return _run_component(component, cfg)
 
     else:
         subcommands = parser.add_subcommands(required=True)
-        func_dict = {c.__name__: c for c in functions}
-        for name, function in func_dict.items():
+        comp_dict = {c.__name__: c for c in components}
+        for name, component in comp_dict.items():
             subparser = ArgumentParser()
-            subparser.add_function_arguments(function, as_positional=as_positional)
             subcommands.add_subcommand(name, subparser)  # type: ignore
+            _add_component_to_parser(component, subparser, as_positional)
 
         cfg = parser.parse_args(args)
-        function = func_dict[cfg['subcommand']]  # type: ignore  # pylint: disable=unsubscriptable-object
-        return function(**cfg[cfg['subcommand']])  # type: ignore  # pylint: disable=unsubscriptable-object
+        subcommand = cfg.pop('subcommand')
+        component = comp_dict[subcommand]
+        return _run_component(component, cfg.get(subcommand))
+
+
+def _add_component_to_parser(component, parser, as_positional):
+    if inspect.isfunction(component):
+        parser.add_function_arguments(component, as_positional=as_positional)
+    else:
+        parser.add_class_arguments(component, as_positional=as_positional)
+        subcommands = parser.add_subcommands(required=True)
+        for key in [k for k, v in inspect.getmembers(component) if callable(v) and k[0] != '_']:
+            subparser = ArgumentParser()
+            subparser.add_method_arguments(component, key, as_positional=as_positional)
+            subcommands.add_subcommand(key, subparser)
+
+
+def _run_component(component, cfg):
+    if 'config' in cfg:
+        del cfg['config']
+    if inspect.isfunction(component):
+        return component(**cfg)
+    else:
+        subcommand = cfg.pop('subcommand')
+        subcommand_cfg = cfg.pop(subcommand)
+        component_obj = component(**cfg)
+        return getattr(component_obj, subcommand)(**subcommand_cfg)
diff --git a/jsonargparse/core.py b/jsonargparse/core.py
@@ -35,6 +35,7 @@
     ActionPath,
     _ActionSubCommands,
     _ActionPrintConfig,
+    _ActionConfigLoad,
     _find_action,
     _is_action_value_list,
 )
@@ -69,39 +70,42 @@ def __init__(self, *args, **kwargs):
         self.register('action', 'parsers', _ActionSubCommands)
 
 
-    def add_argument(self, *args, **kwargs):
+    def add_argument(self, *args, enable_path:bool=False, **kwargs):
         """Adds an argument to the parser or argument group.
 
         All the arguments from `argparse.ArgumentParser.add_argument
         <https://docs.python.org/3/library/argparse.html#argparse.ArgumentParser.add_argument>`_
-        are supported.
+        are supported. Additionally it accepts:
+
+        Args:
+            enable_path: Whether to try parsing path/subconfig when argument is a complex type.
         """
         if 'type' in kwargs:
             if type_in(kwargs['type'], supported_types) or \
                (inspect.isclass(kwargs['type']) and not _issubclass(kwargs['type'], (str, int, float, Enum, Path))):
-                kwargs['action'] = ActionJsonSchema(annotation=kwargs.pop('type'), enable_path=False)
+                kwargs['action'] = ActionJsonSchema(annotation=kwargs.pop('type'), enable_path=enable_path)
             elif _issubclass(kwargs['type'], Enum):
                 kwargs['action'] = ActionEnum(enum=kwargs['type'])
         action = super().add_argument(*args, **kwargs)
         if not hasattr(action, 'completer') and action.type is not None:
             completer_method = FilesCompleterMethod if isinstance(action.type, Path) else TypeCastCompleterMethod
             action_class = action.__class__
-            action.__class__ = action_class.__class__(
+            action.__class__ = action_class.__class__(  # type: ignore
                 action_class.__name__ + 'WithCompleter',
                 (action_class, completer_method),
                 {}
             )
         for key in meta_keys:
             if key in action.dest:
                 raise ValueError('Argument with destination name "'+key+'" not allowed.')
-        parser = self.parser if hasattr(self, 'parser') else self
+        parser = self.parser if hasattr(self, 'parser') else self  # type: ignore
         if action.help is None and \
            hasattr(self, 'formatter_class') and \
-           issubclass(self.formatter_class, DefaultHelpFormatter):
+           issubclass(self.formatter_class, DefaultHelpFormatter):  # type: ignore
             action.help = ' '
         if action.required:
             parser.required_args.add(action.dest)
-            action._required = True
+            action._required = True  # type: ignore
             action.required = False
         if isinstance(action, ActionParser):
             if action._parser == self:
@@ -275,20 +279,13 @@ def _parse_common(
 
         cfg_ns = dict_to_namespace(cfg)
 
-        if hasattr(self, '_print_config') and self._print_config:  # type: ignore
-            sys.stdout.write(self.dump(cfg_ns, skip_none=False, skip_check=True))
+        if hasattr(self, '_print_config'):
+            sys.stdout.write(self.dump(cfg_ns, skip_check=True, **self._print_config))  # type: ignore
             self.exit()
 
         if not skip_check:
             self.check_config(cfg_ns)
 
-        if with_meta or (with_meta is None and self._default_meta):
-            if hasattr(cfg_ns, '__cwd__'):
-                if os.getcwd() not in cfg_ns.__cwd__:
-                    cfg_ns.__cwd__.insert(0, os.getcwd())
-            else:
-                cfg_ns.__cwd__ = [os.getcwd()]
-
         if log_message is not None:
             self._logger.info(log_message)
 
@@ -303,6 +300,7 @@ def parse_args(  # type: ignore[override]
         defaults: bool = True,
         nested: bool = True,
         with_meta: bool = None,
+        _skip_check: bool = False,
     ) -> Union[Namespace, Dict[str, Any]]:
         """Parses command line argument strings.
 
@@ -339,7 +337,7 @@ def parse_args(  # type: ignore[override]
                 defaults=defaults,
                 nested=nested,
                 with_meta=with_meta,
-                skip_check=False,
+                skip_check=_skip_check,
                 cfg_base=namespace,
                 log_message='Parsed command line arguments.',
             )
@@ -517,11 +515,6 @@ def parse_path(
             cfg_str = fpath.get_content()
             parsed_cfg = self.parse_string(cfg_str, cfg_path, ext_vars, env, defaults, nested, with_meta=with_meta,
                                            _skip_logging=True, _skip_check=_skip_check, _base=_base)
-            if with_meta or (with_meta is None and self._default_meta):
-                if self._parse_as_dict:
-                    parsed_cfg['__path__'] = fpath
-                else:
-                    parsed_cfg.__path__ = fpath  # type: ignore
         finally:
             if not fpath.is_url:
                 os.chdir(cwd)
@@ -605,7 +598,7 @@ def _load_cfg(
         try:
             cfg = yaml.safe_load(cfg_str)
         except (yamlParserError, yamlScannerError) as ex:
-            raise TypeError('Problems parsing config :: '+str(ex))
+            raise TypeError('Problems parsing config :: '+str(ex)) from ex
         cfg = namespace_to_dict(_dict_to_flat_namespace(cfg))
         if base is not None:
             cfg = {base+'.'+k: v for k, v in cfg.items()}
@@ -704,7 +697,7 @@ def dump(
 
         def cleanup_actions(cfg, actions):
             for action in actions:
-                if action.help == SUPPRESS or \
+                if (action.help == SUPPRESS and not isinstance(action, _ActionConfigLoad)) or \
                    isinstance(action, ActionConfigFile) or \
                    (skip_none and action.dest in cfg and cfg[action.dest] is None):
                     del cfg[action.dest]
@@ -802,8 +795,8 @@ def save(
             def save_paths(cfg, base=None):
                 replace_keys = {}
                 for key, val in cfg.items():
-                    kbase = key if base is None else base+'.'+key
                     if isinstance(val, dict):
+                        kbase = str(key) if base is None else base+'.'+str(key)
                         if '__path__' in val:
                             val_path = Path(os.path.join(dirname, os.path.basename(val['__path__']())), mode='fc')
                             if not overwrite and os.path.isfile(val_path()):
@@ -982,7 +975,11 @@ def check_values(cfg, base=None):
             check_required(cfg)
             check_values(cfg)
         except (TypeError, KeyError) as ex:
-            raise type(ex)('Config checking failed :: '+str(ex))
+            prefix = 'Configuration check failed :: '
+            message = str(ex)
+            if prefix not in message:
+                message = prefix+message
+            raise type(ex)(message) from ex
 
 
     def instantiate_subclasses(self, cfg:Union[Namespace, Dict[str, Any]]) -> Union[Namespace, Dict[str, Any]]:
@@ -1132,7 +1129,7 @@ def _check_value_key(action:Action, value:Any, key:str, cfg) -> Any:
                     for k, v in enumerate(value):
                         value[k] = action.type(v)
             except (TypeError, ValueError) as ex:
-                raise TypeError('Parser key "'+str(key)+'": '+str(ex))
+                raise TypeError('Parser key "'+str(key)+'": '+str(ex)) from ex
         return value
 
 

diff --git a/jsonargparse/formatters.py b/jsonargparse/formatters.py
@@ -5,7 +5,7 @@
 
 from .util import _get_env_var
 from .typing import type_to_str
-from .actions import ActionParser, ActionEnum, ActionConfigFile
+from .actions import ActionParser, ActionEnum, ActionYesNo, ActionConfigFile
 from .jsonschema import ActionJsonSchema
 
 
@@ -78,7 +78,9 @@ def _expand_help(self, action):
 
     def _get_type_str(self, action):
         type_str = None
-        if action.type is not None:
+        if isinstance(action, ActionYesNo):
+            type_str = 'bool'
+        elif action.type is not None:
             type_str = type_to_str(action.type)
         elif isinstance(action, ActionEnum):
             type_str = type_to_str(action._enum)

diff --git a/jsonargparse/jsonnet.py b/jsonargparse/jsonnet.py
@@ -72,7 +72,7 @@ def __init__(self, **kwargs):
                     try:
                         schema = yaml.safe_load(schema)
                     except (yamlParserError, yamlScannerError) as ex:
-                        raise ValueError('Problems parsing schema :: '+str(ex))
+                        raise ValueError('Problems parsing schema :: '+str(ex)) from ex
                 jsonvalidator.check_schema(schema)
                 self._validator = ActionJsonSchema._extend_jsonvalidator_with_default(jsonvalidator)(schema)
             else:
@@ -119,7 +119,7 @@ def _check_type(self, value, cfg):
                 value[num] = val
             except (TypeError, RuntimeError, yamlParserError, yamlScannerError, jsonschemaValidationError) as ex:
                 elem = '' if not islist else ' element '+str(num+1)
-                raise TypeError('Parser key "'+self.dest+'"'+elem+': '+str(ex))
+                raise TypeError('Parser key "'+self.dest+'"'+elem+': '+str(ex)) from ex
         return value if islist else value[0]
 
 
@@ -175,7 +175,7 @@ def parse(
         try:
             values = yaml.safe_load(_jsonnet.evaluate_snippet(fname, snippet, ext_vars=ext_vars, ext_codes=ext_codes))
         except RuntimeError as ex:
-            raise ParserError('Problems evaluating jsonnet "'+fname+'" :: '+str(ex))
+            raise ParserError('Problems evaluating jsonnet "'+fname+'" :: '+str(ex)) from ex
         if self._validator is not None:
             self._validator.validate(values)
         if with_meta and isinstance(values, dict) and fpath is not None:

diff --git a/jsonargparse/jsonschema.py b/jsonargparse/jsonschema.py
@@ -18,6 +18,7 @@
     ParserError,
     strip_meta,
     import_object,
+    _load_config,
     _check_unknown_kwargs,
     _issubclass,
 )
@@ -26,7 +27,6 @@
     jsonschemaValidationError,
     jsonschema_support,
     import_jsonschema,
-    get_config_read_mode,
     files_completer,
     argcomplete_warn_redraw_prompt,
 )
@@ -90,7 +90,7 @@ def __init__(self, **kwargs):
                 try:
                     schema = yaml.safe_load(schema)
                 except (yamlParserError, yamlScannerError) as ex:
-                    raise ValueError('Problems parsing schema :: '+str(ex))
+                    raise ValueError('Problems parsing schema :: '+str(ex)) from ex
             jsonvalidator.check_schema(schema)
             self._validator = self._extend_jsonvalidator_with_default(jsonvalidator)(schema)
             self._enable_path = kwargs.get('enable_path', True)
@@ -136,18 +136,7 @@ def _check_type(self, value, cfg=None):
             value = [value]
         for num, val in enumerate(value):
             try:
-                fpath = None
-                if isinstance(val, str) and val.strip() != '':
-                    parsed_val = yaml.safe_load(val)
-                    if not isinstance(parsed_val, str):
-                        val = parsed_val
-                if self._enable_path and isinstance(val, str):
-                    try:
-                        fpath = Path(val, mode=get_config_read_mode())
-                    except TypeError:
-                        pass
-                    else:
-                        val = yaml.safe_load(fpath.get_content())
+                val, fpath = _load_config(val, enable_path=self._enable_path, flat_namespace=False)
                 if isinstance(val, Namespace):
                     val = namespace_to_dict(val)
                 val = self._adapt_types(val, self._annotation, self._subschemas, reverse=True)
@@ -161,7 +150,7 @@ def _check_type(self, value, cfg=None):
                 value[num] = val
             except (TypeError, yamlParserError, yamlScannerError, jsonschemaValidationError) as ex:
                 elem = '' if not islist else ' element '+str(num+1)
-                raise TypeError('Parser key "'+self.dest+'"'+elem+': '+str(ex))
+                raise TypeError('Parser key "'+self.dest+'"'+elem+': '+str(ex)) from ex
         return value if islist else value[0]
 
 
@@ -236,7 +225,7 @@ def validate_adapt(v, subschema):
                             init_args = parser.instantiate_subclasses(val['init_args'])
                             val = val_class(**init_args)  # pylint: disable=not-a-mapping
                 except (ImportError, ModuleNotFound, AttributeError, AssertionError, ParserError) as ex:
-                    raise ParserError('Problem with given class_path "'+val['class_path']+'" :: '+str(ex))
+                    raise ParserError('Problem with given class_path "'+val['class_path']+'" :: '+str(ex)) from ex
             return val
 
         elif annotation.__origin__ == Union:

diff --git a/jsonargparse/optionals.py b/jsonargparse/optionals.py
@@ -49,55 +49,55 @@ def import_jsonschema(importer):
         from jsonschema import Draft7Validator as jsonvalidator
         return jsonschema, jsonvalidator
     except (ImportError, ModuleNotFound) as ex:
-        raise ImportError('jsonschema package is required by '+importer+' :: '+str(ex))
+        raise ImportError('jsonschema package is required by '+importer+' :: '+str(ex)) from ex
 
 
 def import_jsonnet(importer):
     try:
         import _jsonnet
         return _jsonnet
     except (ImportError, ModuleNotFound) as ex:
-        raise ImportError('jsonnet package is required by '+importer+' :: '+str(ex))
+        raise ImportError('jsonnet package is required by '+importer+' :: '+str(ex)) from ex
 
 
 def import_url_validator(importer):
     try:
         from validators.url import url as url_validator
         return url_validator
     except (ImportError, ModuleNotFound) as ex:
-        raise ImportError('validators package is required by '+importer+' :: '+str(ex))
+        raise ImportError('validators package is required by '+importer+' :: '+str(ex)) from ex
 
 
 def import_requests(importer):
     try:
         import requests
         return requests
     except (ImportError, ModuleNotFound) as ex:
-        raise ImportError('requests package is required by '+importer+' :: '+str(ex))
+        raise ImportError('requests package is required by '+importer+' :: '+str(ex)) from ex
 
 
 def import_docstring_parse(importer):
     try:
         from docstring_parser import parse as docstring_parse
         return docstring_parse
     except (ImportError, ModuleNotFound) as ex:
-        raise ImportError('docstring-parser package is required by '+importer+' :: '+str(ex))
+        raise ImportError('docstring-parser package is required by '+importer+' :: '+str(ex)) from ex
 
 
 def import_argcomplete(importer):
     try:
         import argcomplete
         return argcomplete
     except (ImportError, ModuleNotFound) as ex:
-        raise ImportError('argcomplete package is required by '+importer+' :: '+str(ex))
+        raise ImportError('argcomplete package is required by '+importer+' :: '+str(ex)) from ex
 
 
 def import_dataclasses(importer):
     try:
         import dataclasses
         return dataclasses
     except (ImportError, ModuleNotFound) as ex:
-        raise ImportError('dataclasses package is required by '+importer+' :: '+str(ex))
+        raise ImportError('dataclasses package is required by '+importer+' :: '+str(ex)) from ex
 
 
 def set_url_support(enabled:bool):

diff --git a/jsonargparse/signatures.py b/jsonargparse/signatures.py
@@ -5,7 +5,8 @@
 from typing import Union, Optional, List, Container, Type, Callable
 
 from .util import _issubclass
-from .actions import ActionEnum
+from .actions import ActionEnum, _ActionConfigLoad
+from .typing import is_optional
 from .jsonschema import ActionJsonSchema
 from .optionals import docstring_parser_support, import_docstring_parse, dataclasses_support, import_dataclasses
 
@@ -92,9 +93,9 @@ def add_method_arguments(
         if not inspect.isclass(theclass):
             raise ValueError('Expected a class object.')
         if not hasattr(theclass, themethod) or not callable(getattr(theclass, themethod)):
-            raise ValueError('Expected the method to a callable member of the class.')
+            raise ValueError('Expected the method to be a callable member of the class.')
 
-        skip_first = False if isinstance(theclass.__dict__[themethod], staticmethod) else True
+        skip_first = not isinstance(inspect.getattr_static(theclass, themethod), staticmethod)
         themethod = getattr(theclass, themethod)
 
         return self._add_signature_arguments([themethod],
@@ -213,6 +214,8 @@ def update_has_args_kwargs(base, has_args=True, has_kwargs=True):
                 doc_group = str(objects[0])
             name = objects[0].__name__ if nested_key is None else nested_key
             group = self.add_argument_group(doc_group, name=name)  # type: ignore
+            if nested_key is not None:
+                group.add_argument('--'+nested_key, action=_ActionConfigLoad)  # type: ignore
 
         ## Add objects arguments ##
         added_args = set()
@@ -247,6 +250,8 @@ def update_has_args_kwargs(base, has_args=True, has_kwargs=True):
                 kwargs = {'help': doc_params.get(name)}
                 if not is_required:
                     kwargs['default'] = default
+                    if default is None and not is_optional(annotation, object):
+                        annotation = Optional[annotation]
                 elif not as_positional:
                     kwargs['required'] = True
                 if annotation in {str, int, float, bool} or \

diff --git a/jsonargparse/util.py b/jsonargparse/util.py
@@ -4,6 +4,7 @@
 import re
 import sys
 import stat
+import yaml
 import inspect
 import logging
 from copy import deepcopy
@@ -13,7 +14,13 @@
 from yaml.parser import ParserError as yamlParserError
 from yaml.scanner import ScannerError as yamlScannerError
 
-from .optionals import ModuleNotFound, url_support, import_requests, import_url_validator
+from .optionals import (
+    ModuleNotFound,
+    url_support,
+    import_requests,
+    import_url_validator,
+    get_config_read_mode,
+)
 
 
 __all__ = [
@@ -32,14 +39,38 @@
 null_logger = logging.Logger('jsonargparse_null_logger')
 null_logger.addHandler(logging.NullHandler())
 
-meta_keys = {'__cwd__', '__path__', '__default_config__'}
+meta_keys = {'__path__', '__default_config__'}
 
 
 class ParserError(Exception):
     """Error raised when parsing a value fails."""
     pass
 
 
+def _load_config(value, enable_path=True, flat_namespace=True):
+    """Parses yaml config in a string or a path"""
+    cfg_path = None
+    if isinstance(value, str) and value.strip() != '':
+        parsed_val = yaml.safe_load(value)
+        if not isinstance(parsed_val, str):
+            value = parsed_val
+    if enable_path and isinstance(value, str):
+        try:
+            cfg_path = Path(value, mode=get_config_read_mode())
+        except TypeError:
+            pass
+        else:
+            value = yaml.safe_load(cfg_path.get_content())
+
+    if flat_namespace:
+        value = _dict_to_flat_namespace(value)
+        if cfg_path is not None:
+            setattr(value, '__path__', cfg_path)
+        return value
+
+    return value, cfg_path
+
+
 def _get_key_value(cfg, key, parent=False):
     """Gets the value for a given key in a config object (dict or argparse.Namespace)."""
     def key_in_cfg(cfg, key):
@@ -310,7 +341,7 @@ def __init__(
                 try:
                     requests.head(abs_path).raise_for_status()
                 except requests.HTTPError as ex:
-                    raise TypeError(abs_path+' HEAD not accessible :: '+str(ex))
+                    raise TypeError(abs_path+' HEAD not accessible :: '+str(ex)) from ex
         elif not skip_check:
             ptype = 'Directory' if 'd' in mode else 'File'
             if 'c' in mode:

diff --git a/jsonargparse_tests/cli_tests.py b/jsonargparse_tests/cli_tests.py
@@ -24,6 +24,34 @@ def cmd2(a2: str = 'X'):
         self.assertEqual('Y', CLI(functions, args=['cmd2', '--a2=Y']))
 
 
+    def test_single_class_cli(self):
+        class Class1:
+            def __init__(self, i1: str):
+                self.i1 = i1
+            def method1(self, m1: int):
+                return self.i1, m1
+
+        self.assertEqual(('0', 2), CLI(Class1, args=['0', 'method1', '2']))
+
+
+    def test_function_and_class_cli(self):
+        def cmd1(a1: int):
+            return a1
+
+        class Cmd2:
+            def __init__(self, i1: str = 'd'):
+                self.i1 = i1
+            def method1(self, m1: float):
+                return self.i1, m1
+            def method2(self, m1: int = 0):
+                return self.i1, m1
+
+        components = [cmd1, Cmd2]
+        self.assertEqual(5, CLI(components, args=['cmd1', '5']))
+        self.assertEqual(('d', 1.2), CLI(components, args=['Cmd2', 'method1', '1.2']))
+        self.assertEqual(('b', 3), CLI(components, args=['Cmd2', '--i1=b', 'method2', '--m1=3']))
+
+
     def test_empty_context(self):
         def empty_context():
             CLI()
@@ -32,13 +60,23 @@ def empty_context():
 
 
     def test_non_empty_context(self):
-        def non_empty_context():
+        def non_empty_context_1():
             def function(a1: float):
                 return a1
 
             return CLI(args=['6.7'])
 
-        self.assertEqual(6.7, non_empty_context())
+        def non_empty_context_2():
+            class Class1:
+                def __init__(self, i1: str):
+                    self.i1 = i1
+                def method1(self, m1: int):
+                    return self.i1, m1
+
+            return CLI(args=['a', 'method1', '2'])
+
+        self.assertEqual(6.7, non_empty_context_1())
+        self.assertEqual(('a', 2), non_empty_context_2())
 
 
 if __name__ == '__main__':

diff --git a/jsonargparse_tests/core_tests.py b/jsonargparse_tests/core_tests.py
@@ -94,8 +94,6 @@ def test_parse_path(self):
         self.assertEqual(cfg2, parser.parse_path(yaml_file, defaults=False))
         self.assertNotEqual(cfg2, parser.parse_path(yaml_file, defaults=True))
         self.assertNotEqual(cfg1, parser.parse_path(yaml_file, defaults=False))
-        self.assertTrue(hasattr(parser.parse_path(yaml_file, with_meta=True), '__cwd__'))
-        self.assertFalse(hasattr(parser.parse_path(yaml_file), '__cwd__'))
 
         with open(yaml_file, 'w') as output_file:
             output_file.write(example_yaml+'  val2: eight\n')
@@ -191,7 +189,6 @@ def test_parse_as_dict(self):
         with open('config.json', 'w') as f:
             f.write('{}')
         parser = ArgumentParser(parse_as_dict=True, default_meta=True)
-        self.assertEqual({'__path__', '__cwd__'}, set(parser.parse_path('config.json').keys()))
 
 
 class ArgumentFeaturesTests(unittest.TestCase):
@@ -576,7 +573,6 @@ def test_save(self):
 
         cfg2 = parser.parse_path(main_file, with_meta=True)
         self.assertEqual(namespace_to_dict(cfg1), strip_meta(cfg2))
-        self.assertEqual(cfg2.__path__(), main_file)
         self.assertEqual(cfg2.parser.__path__(absolute=False), 'parser.yaml')
         if jsonschema_support:
             self.assertEqual(cfg2.schema.__path__(absolute=False), 'schema.yaml')
@@ -631,6 +627,13 @@ def test_print_config(self):
         outval = yaml.safe_load(out.getvalue())
         self.assertEqual(outval, {'g1': {'v2': '2'}, 'g2': {'v3': None}, 'v1': 1})
 
+        out = StringIO()
+        with redirect_stdout(out), self.assertRaises(SystemExit):
+            parser.parse_args(['--print_config=skip_null'])
+
+        outval = yaml.safe_load(out.getvalue())
+        self.assertEqual(outval, {'g1': {'v2': '2'}, 'v1': 1})
+
 
 class ConfigFilesTests(TempDirTestCase):
 
@@ -683,9 +686,6 @@ def test_ActionConfigFile_and_ActionPath(self):
         self.assertEqual(abs_yaml_file, os.path.realpath(cfg.file(absolute=True)))
         self.assertRaises(ParserError, lambda: parser.parse_args(['--cfg', abs_yaml_file+'~']))
 
-        cfg = parser.parse_args(['--cfg', abs_yaml_file, '--cfg', abs_yaml_file])
-        self.assertEqual(3, len(cfg.__cwd__))
-
         cfg = parser.parse_args(['--cfg', 'file: '+abs_yaml_file+'\ndir: '+self.tmpdir+'\n'])
         self.assertEqual(self.tmpdir, os.path.realpath(cfg.dir(absolute=True)))
         self.assertEqual(None, cfg.cfg[0])

diff --git a/jsonargparse_tests/formatters_tests.py b/jsonargparse_tests/formatters_tests.py
@@ -17,6 +17,7 @@ def test_default_help_formatter(self):
         parser2 = ArgumentParser()
         parser2.add_argument('--v4')
         parser.add_argument('--g2', action=ActionParser(parser=parser2))
+        parser.add_argument('--v5', action=ActionYesNo, default=True, help='Option v5.')
 
         os.environ['COLUMNS'] = '150'
         out = StringIO()
@@ -50,6 +51,10 @@ def test_default_help_formatter(self):
         self.assertIn('APP_G2', outval)
         self.assertIn('--g2.help', outval)
 
+        self.assertIn('--v5, --no_v5', outval)
+        self.assertIn('APP_V5', outval)
+        self.assertIn('Option v5. (type: bool, default: True)', outval)
+
 
 if __name__ == '__main__':
     unittest.main(verbosity=2)
diff --git a/jsonargparse_tests/signatures_tests.py b/jsonargparse_tests/signatures_tests.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 
+import yaml
 from enum import Enum
 from io import StringIO
 from typing import Dict, List, Tuple, Optional, Union, Any
@@ -386,6 +387,17 @@ def __init__(self, c1: Optional[Class1]):
         self.assertEqual(2.3, cfg.c1.a2)
 
 
+    def test_implicit_optional(self):
+
+        def func(a1: int = None):
+            return a1
+
+        parser = ArgumentParser(error_handler=None)
+        parser.add_function_arguments(func)
+
+        self.assertIsNone(parser.parse_args(['--a1=null']).a1)
+
+
     @unittest.skipIf(not docstring_parser_support, 'docstring-parser package is required')
     def test_docstring_parse_fail(self):
 
@@ -409,5 +421,56 @@ def __init__(self, a1: int = 1):
             self.assertNotIn('a1 description', help_str.getvalue())
 
 
+@unittest.skipIf(not jsonschema_support, 'jsonschema package is required')
+class SignaturesConfigTests(TempDirTestCase):
+
+    def test_add_function_arguments_config(self):
+
+        def func(a1 = '1',
+                 a2: float = 2.0,
+                 a3: bool = False):
+            return a1
+
+        parser = ArgumentParser(error_handler=None, default_meta=False)
+        parser.add_function_arguments(func, 'func')
+
+        cfg_path = 'config.yaml'
+        with open(cfg_path, 'w') as f:
+            f.write(yaml.dump({'a1': 'one', 'a3': True}))
+
+        cfg = parser.parse_args(['--func', cfg_path])
+        self.assertEqual(cfg.func, Namespace(a1='one', a2=2.0, a3=True))
+
+        cfg = parser.parse_args(['--func={"a1": "ONE"}'])
+        self.assertEqual(cfg.func, Namespace(a1='ONE', a2=2.0, a3=False))
+
+        self.assertRaises(ParserError, lambda: parser.parse_args(['--func="""']))
+
+
+    def test_config_within_config(self):
+
+        def func(a1 = '1',
+                 a2: float = 2.0,
+                 a3: bool = False):
+            return a1
+
+        parser = ArgumentParser(error_handler=None)
+        parser.add_argument('--cfg', action=ActionConfigFile)
+        parser.add_function_arguments(func, 'func')
+
+        cfg_path = 'subdir/config.yaml'
+        subcfg_path = 'subsubdir/func_config.yaml'
+        os.mkdir('subdir')
+        os.mkdir('subdir/subsubdir')
+        with open(cfg_path, 'w') as f:
+            f.write('func: '+subcfg_path+'\n')
+        with open(os.path.join('subdir', subcfg_path), 'w') as f:
+            f.write(yaml.dump({'a1': 'one', 'a3': True}))
+
+        cfg = parser.parse_args(['--cfg', cfg_path])
+        self.assertEqual(str(cfg.func.__path__), subcfg_path)
+        self.assertEqual(strip_meta(cfg.func), {'a1': 'one', 'a2': 2.0, 'a3': True})
+
+
 if __name__ == '__main__':
     unittest.main(verbosity=2)
diff --git a/setup.cfg b/setup.cfg
@@ -48,7 +48,7 @@ doc =
 
 [metadata]
 name = jsonargparse
-version = 3.1.0
+version = 3.2.1
 description = Parsing of command line options, yaml/jsonnet config files and/or environment variables based on argparse.
 long_description_content_type = text/x-rst
 author = Mauricio Villegas
Original file line number	Diff line number	Diff line change
		@@ -20,4 +20,4 @@
		)


		__version__ = '3.1.0'
		__version__ = '3.2.1'