Added support for checking file extension of PathLikes

pydub/audio_segment.py

@@ -447,6 +447,25 @@ def is_format(f):
                 return True
             if isinstance(orig_file, basestring):
                 return orig_file.lower().endswith(".{0}".format(f))
+            if sys.version_info >= (3, 6):
+                try:
+                    path = os.fspath(orig_file)
+
+                    if isinstance(path, bytes):
+                        try:
+                            path = path.decode(sys.getdefaultencoding())    
+                        except Exception:
+                            pass
+
+                    return path.lower().endswith(".{0}".format(f))
+                except TypeError:
+                    # Either orig_file was not a str, bytes, or PathLike
+                    # object, or os.fspath() returned a byte string and and we
+                    # failed to decode it, then endswith() tried to compare
+                    # that with a regular str. In either case, we can't discern
+                    # the file extension.
+                    pass
+
             return False
 
         if is_format("wav"):