Error: "'utf-8' codec can't decode byte 0xd6 in position 4: invalid continuation byte" when trying to open .wav file

I am receiving my ".wav" file in a django view as an "InMemoryUploadedFile" then converting it to bytes:

views.py

import functions.bytes_to_wav_wave
     
    if voice_value:
        # convert to bytes
        file_content_bytes = voice_value.read()
        wav_sound = bytes_to_wav_in_memory(file_content_bytes,1,2,10)
        buffer = io.BytesIO(wav_sound)

        try:
            file_w = bytes_to_wav_wave(file_content_bytes,'output_wave.wav', 1, 2, 44100)
        except Exception as e:
            print(e)
            
        with open('output_wave.wav', 'r') as file:
            content = file.read()

While the function "bytes_to_wav_wave" is:

functions.py

def bytes_to_wav_wave(audio_bytes, filename, nchannels, sampwidth, framerate):
    """
    Converts raw audio bytes to a WAV file using the wave module.

    Args:
        audio_bytes (bytes): The raw audio data.
        filename (str): The name of the output WAV file.
        nchannels (int): Number of audio channels (e.g., 1 for mono, 2 for stereo).
        sampwidth (int): Sample width in bytes (e.g., 2 for 16-bit audio).
        framerate (int): Frame rate or sample rate in Hz (e.g., 44100).
    """
    with wave.open(filename, 'wb') as wf:
        wf.setnchannels(nchannels)
        wf.setsampwidth(sampwidth)
        wf.setframerate(framerate)
        wf.writeframes(audio_bytes)


# Example usage:
# Assuming 'raw_audio_data' is your bytes object containing audio data
# bytes_to_wav_wave(raw_audio_data, 'output_wave.wav', 1, 2, 44100)

But once I finish the conversion and come to opening my file with:

Views.py

try:
    file_w = bytes_to_wav_wave(file_content_bytes,'output_wave.wav', 1, 2, 44100)
except Exception as e:
    print(e)

try:
    with open('output_wave.wav', 'r') as file:
        content = file.read()
except Exception as e:
    print("in try")
    print(e)

The "except" block catches the error:

**'utf-8' codec can't decode byte 0xc6 in position 4: invalid continuation byte **

Using 'r' opens a file in textmode. (see: https://docs.python.org/3/library/functions.html#open)

.wav needs to be opened in binary mode 'rb' (.wav file format definition: https://en.wikipedia.org/wiki/WAV).

In textmode, python tries to decode textmode files as utf by default - thus the utf decoding error.

Views.py should read:

  with open('output_wave.wav', 'rb') as file: