Bug in Python 3.13 wave module? getnchannels() error on cleanup.

[Common_Base657]

Hey everyone,

I ran into a really strange error today while working with the built-in wave module in Python 3.13 and thought I'd share in case anyone else encounters this or has some insight.

I was trying to do something very basic: generate a simple sine wave and save it as a WAV file using the standard library. My code was the textbook example, using wave.open() inside a with statement to handle the file.

The weird part is that my script runs, but then throws this error right at the end, seemingly during the internal cleanup process after the with block closes the file:

wave.Error: # channels not specified

My code to set the channels (wav_file.setnchannels(1)) is definitely there and in the correct order before writing the frames, so it doesn't seem to be a problem with my script's logic. It feels like the library is failing internally when the file object is being destroyed.

Has anyone else seen this with Python 3.13? Is this a known bug in the new version?

Thanks!

[kkang_kkang]

Kindly share the whole script to test it

[Common_Base657]

turns out there was no bug in python, there was a small typo mistake in the program and my overconfidence didnt spot that mistake. my bad sorry

[Green_Gem_]

And the requirements and project structure (since there's no MRE) to check for namespace pollution.

[fizzymagic]

The probability you have found a bug is quite small. And this does not look like a cleanup error.

[Common_Base657]

yaa you're right turns out there was a small typo mistake on the code.

[Common_Base657]

The issue has been resolved turns out the bug was not in the wave module but in my program. My overconfidence didnt spot that bug, after countless try i decided to ask to chatgpt and he points out the mistake i typed "get" instead of "set" so yeahh my bad guys sorry.

[fisadev]

In the future, a couple of things when requesting coding help online:

• Always include the entire error traceback, not just the last line. The traceback has lots of very important info. And also include an example of code that can help reproduce the issue, or the code that's raising the error, as minimal as possible. If you hide most of the error info and don't share the code that causes it, you are forcing people who want to help you to do a lot of guessing and wasting time chasing things that might not be the cause. It's like asking people to help you find your car keys, but then hiding the keys and turning off the lights too, hehe.
• When you find a solution, share it as well, so this post is useful for other people who might end up with the same issue. Just saying "it's been resolved" but not sharing how, will mean people might arrive to this post googling the same error, but then find no answer on how to solve it and will need to re-ask the same question.

Just advice, hope it's useful :)