Record system or output device audio using Python Pyaudio

Question

The output device is typically used for audio playback but in this case I want to record/read/capture the system audio (or other output device) for use in transcription. I've heard this is called "Loopback" but it's not supported by pyaudio library. Is there another solution to easily capture both streams?

          if not record_thread:
                stream_in = None
                stream_out = None

                if device_index is not None:
                    stream_in = pa.open(
                        format=pyaudio.paInt16,
                        channels=1,
                        rate=sample_rate,
                        input=True,
                        frames_per_buffer=chunk_size,
                        input_device_index=device_index,
                    )
                else:
                    stream_in = None
                if output_index is not None:
                    stream_out = pyaudio.PyAudio().open(
                        format=pyaudio.paInt16,
                        channels=2, #usually 2 because stereo
                        frames_per_buffer=chunk_size,
                        rate=sample_rate,
                        input=True,
                        input_device_index=output_index,
                    )
                else:
                    stream_out = None

                out_data = stream_out.read(chunk_size)
                record_thread = Thread(target=recording_thread, args=[stream_in, out_data])
                run_record_thread = True
                record_thread.start()
```