Result object now resolves as False when unsuccessful and no longer e…

…rrors on requests for pods or info. Fixes #13.

CHANGES.rst

@@ -3,6 +3,8 @@ v4.3.0
 
 * Added ``Client.from_env()`` to initialize a client loading the
   API key from the keyring or environment.
+* #13: ``Result`` objects now resolve as False and return empty
+  ``info`` and ``pods`` attributes when query was unsuccessful.
 
 v4.2.0
 ======

wolframalpha/__init__.py

@@ -235,10 +235,6 @@ class Result(ErrorHandler, Document):
     Handles processing the response for the programmer.
     """
 
-    _attr_types = dict(
-        pod=Pod.from_doc,
-    )
-
     def __init__(self, stream):
         doc = xmltodict.parse(stream, dict_constructor=dict)['queryresult']
         super(Result, self).__init__(doc)
@@ -252,7 +248,7 @@ def info(self):
 
     @property
     def pods(self):
-        return self.pod
+        return Pod.from_doc(self.get('pod'))
 
     @property
     def assumptions(self):
@@ -268,6 +264,9 @@ def __iter__(self):
     def __len__(self):
         return sum(1 for _ in self.info)
 
+    def __bool__(self):
+        return bool(len(self))
+
     @property
     def results(self):
         """