Error: python3 -c "import soundcard"

[AlexanderShad]

Hi

python3 -c "import soundcard"

Traceback (most recent call last):
File "", line 1, in
File "/usr/lib/python3/site-packages/soundcard/init.py", line 4, in
from soundcard.pulseaudio import *
File "/usr/lib/python3/site-packages/soundcard/pulseaudio.py", line 290, in
_pulse = _PulseAudio()
^^^^^^^^^^^^^
File "/usr/lib/python3/site-packages/soundcard/pulseaudio.py", line 95, in init
self.context = _pa.pa_context_new(self.mainloop_api, self._infer_program_name().encode())
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3/site-packages/soundcard/pulseaudio.py", line 114, in _infer_program_name
return sys.argv[1][:30] + "..."
~~~~~~~~^^^
IndexError: list index out of range

[bastibe]

According to the documentation, this can not happen. What is your sys.argv in this case?

[AlexanderShad]

According to the documentation, this can not happen.

Hello

The error is not reproduced when

return sys.argv[0][:30] + "..."

[AlexanderShad]

I don't know how critical it is from your point of view.

But I got a request
https://bugzilla.altlinux.org/55035

to fix the import call I changed the range

[AlexanderShad]

https://git.altlinux.org/gears/p/python3-module-soundcard.git?p=python3-module-soundcard.git;a=blob;f=.gear/pulseaudio-0.4.4-alt-fixes.patch

[AlexanderShad]

as far as I understand, if there is only 1 sys.argv[0], and there is no second one, i.e. there is no sys.argv[1], then it falls outside the range. That is, when there is nothing else except "-c".

[bastibe]

This feature was tested, so I'm sure the current behavior is reasonable on some operating systems or configurations.

However, the feature itself is not critical. It's merely setting the program name that is reported to pulseaudio. We can just fall back to something generic if the heuristics fail.

[AlexanderShad]

For example, the Pyzam package, which uses SoundCard in his work, works normally, both with this error and with a changed range.

But I could not ignore the error report in bugzilla, so I wrote issue you too

[bastibe]

If you'd like to provide a fix (even a simple try/catch) as a pull request, I'll happily merge it.

[AlexanderShad]

Are you suggesting to do something like this?

if prog_name == "-c":
    try
       return sys.argv[1][:30] + "..."
    except IndexError:
       return sys.argv[0][:30] + "..."
    except Exception:
      pass

or simply

if prog_name == "-c":
    try
       return sys.argv[1][:30] + "..."
    except IndexError:
      pass

[bastibe]

Yes, that would be the simplest solution. But I'm all ears for a better one.

[AlexanderShad]

Hello

I did it a little differently.
Please take a look my PR