I am following a tutorial on PyDub. The very first exercise is to play a WAV file. Here is my adapted code. I’m not too worried about the warning at this point, as I am trying to resolve the [Errno 13] resulting from the final command play(wav_file):

>>> import os
>>> os.chdir('C:/cygwin64/home/User.Name/Some.Path')
>>> from pydub import AudioSegment
>>> from pydub.playback import play
>>> wav_file = AudioSegment.from_file(file = "SomeFile.wav", format = "wav")

C:UsersUser.Nameanaconda3envspy39libsite-packagespydubutils.py:170: RuntimeWarning: Couldn't find ffmpeg or avconv - defaulting to ffmpeg, but may not work
  warn("Couldn't find ffmpeg or avconv - defaulting to ffmpeg, but may not work", RuntimeWarning)

>>> play(wav_file)

C:UsersUser.Nameanaconda3envspy39libsite-packagespydubutils.py:184: RuntimeWarning: Couldn't find ffplay or avplay - defaulting to ffplay, but may not work
  warn("Couldn't find ffplay or avplay - defaulting to ffplay, but may not work", RuntimeWarning)
Traceback (most recent call last):

  Cell In[5], line 1
    play(wav_file)

  File ~anaconda3envspy39libsite-packagespydubplayback.py:71 in play
    _play_with_ffplay(audio_segment)

  File ~anaconda3envspy39libsite-packagespydubplayback.py:15 in _play_with_ffplay
    seg.export(f.name, "wav")

  File ~anaconda3envspy39libsite-packagespydubaudio_segment.py:867 in export
    out_f, _ = _fd_or_path_or_tempfile(out_f, 'wb+')

  File ~anaconda3envspy39libsite-packagespydubutils.py:60 in _fd_or_path_or_tempfile
    fd = open(fd, mode=mode)

PermissionError: [Errno 13] Permission denied: 'C:\Users\User.Name\AppData\Local\Temp\tmpryjpscsv.wav'

Much googling reveals the likely error to be that on Windows, you cannot repeatedly open a file without closing it. The vary last frame in the stack trace is line 60 of utils.py:

/c/Users/User.Name/anaconda3/envs/py39/lib/site-packages/pydub/utils.py
-----------------------------------------------------------------------
53 def _fd_or_path_or_tempfile(fd, mode='w+b', tempfile=True):
54     close_fd = False
55     if fd is None and tempfile:
56         fd = TemporaryFile(mode=mode)
57         close_fd = True
58
59     if isinstance(fd, basestring):
60         fd = open(fd, mode=mode)
61         close_fd = True
62
63     try:
64         if isinstance(fd, os.PathLike):
65             fd = open(fd, mode=mode)
66             close_fd = True
67     except AttributeError:
68         # module os has no attribute PathLike, so we're on python < 3.6.
69         # The protocol we're trying to support doesn't exist, so just pass.
70         pass
71
72     return fd, close_fd

I noticed that whenever fd is assigned an open file, the close_fd flag is set to True. I can use this to avoid multiple reopenings. Lines 60 and 65 represent potential sites of [Errno 13]. Would it be robust to AND the immediately preceding if conditions as follows?

59     if not close_fd and isinstance(fd, basestring):
64         if not close_fd and isinstance(fd, os.PathLike):

The 2nd of the two conditional openings refers to os.PathLike. While I can find webpages on that, I can’t find a simple explanation. So I’m not sure what the enclosing try block is meant to do. I hope that understanding it is not necessary if the logic at the microscopic level is robust enough for general situations, i.e., if not close_fd and ....