Fix docs

patoolib/util.py

@@ -36,10 +36,10 @@ except ImportError:
         of os.environ.get("PATH"), or can be overridden with a custom search
         path.
         """
-        # Check that a given file can be accessed with the correct mode.
-        # Additionally check that `file` is not a directory, as on Windows
-        # directories pass the os.access check.
         def _access_check(fn, mode):
+            """Check that a given file can be accessed with the correct mode.
+            Additionally check that `fn` is not a directory, as on Windows
+            directories pass the os.access check."""
             return (os.path.exists(fn) and os.access(fn, mode)
                     and not os.path.isdir(fn))
         # If we're given a path with a directory part, look it up directly rather