Merge pull request #17530 from BvB93/fspath

ENH: Allow `ctypeslib.load_library` to take any path-like object

doc/release/upcoming_changes/17530.improvement.rst

@@ -0,0 +1,5 @@
+`ctypeslib.load_library` can now take any path-like object
+-----------------------------------------------------------------------
+All parameters in the can now take any :term:`python:path-like object`.
+This includes the likes of strings, bytes and objects implementing the
+:meth:`__fspath__<os.PathLike.__fspath__>` protocol.

numpy/ctypeslib.py

@@ -90,18 +90,23 @@ def _dummy(*args, **kwds):
     def load_library(libname, loader_path):
         """
         It is possible to load a library using
+
         >>> lib = ctypes.cdll[<full_path_name>] # doctest: +SKIP
 
         But there are cross-platform considerations, such as library file extensions,
         plus the fact Windows will just load the first library it finds with that name.
         NumPy supplies the load_library function as a convenience.
 
+        .. versionchanged:: 1.20.0
+            Allow libname and loader_path to take any
+            :term:`python:path-like object`.
+
         Parameters
         ----------
-        libname : str
+        libname : path-like
             Name of the library, which can have 'lib' as a prefix,
             but without an extension.
-        loader_path : str
+        loader_path : path-like
             Where the library can be found.
 
         Returns
@@ -120,6 +125,10 @@ def load_library(libname, loader_path):
             warnings.warn("All features of ctypes interface may not work "
                           "with ctypes < 1.0.1", stacklevel=2)
 
+        # Convert path-like objects into strings
+        libname = os.fsdecode(libname)
+        loader_path = os.fsdecode(loader_path)
+
         ext = os.path.splitext(libname)[1]
         if not ext:
             # Try to load library with platform-specific name, otherwise

numpy/tests/test_ctypeslib.py

@@ -1,6 +1,7 @@
 import sys
 import pytest
 import weakref
+from pathlib import Path
 
 import numpy as np
 from numpy.ctypeslib import ndpointer, load_library, as_array
@@ -37,13 +38,15 @@
                     reason="Known to fail on cygwin")
 class TestLoadLibrary:
     def test_basic(self):
-        try:
-            # Should succeed
-            load_library('_multiarray_umath', np.core._multiarray_umath.__file__)
-        except ImportError as e:
-            msg = ("ctypes is not available on this python: skipping the test"
-                   " (import error was: %s)" % str(e))
-            print(msg)
+        loader_path = np.core._multiarray_umath.__file__
+
+        out1 = load_library('_multiarray_umath', loader_path)
+        out2 = load_library(Path('_multiarray_umath'), loader_path)
+        out3 = load_library('_multiarray_umath', Path(loader_path))
+        out4 = load_library(b'_multiarray_umath', loader_path)
+
+        assert isinstance(out1, ctypes.CDLL)
+        assert out1 is out2 is out3 is out4
 
     def test_basic2(self):
         # Regression for #801: load_library with a full library name