Concatenate wav files into one evenly-spaced wav file (128-file limit)

concat.py

# Concatenate wav files into one evenly spaced wav file
# Requires sox and PySox https://github.com/rabitt/pysox
# License: Public domain

import sox, os

def combine_files(folder, files, out_filename, sample_rate, channels, bit_depth):
    combine = sox.Combiner()
    combine.convert(sample_rate, channels, bit_depth)
    out_files = [f"{folder}/{file}" for file in files]
    combine.build(out_files, out_filename, 'concatenate')
    print(f"{out_filename} created")
    return

folders = next(os.walk('.'))[1]
for folder in folders:
    sample_rate = 44100
    channels = 2
    bit_depth = 16
    all_files = next(os.walk(folder))[2]
    one_shots = [file for file in all_files if ".wav" in file.lower()]
    one_shots.sort()
    out_filename = ""
    concat_files = []
    max_samples = 0
    for file in one_shots:
        try:
            file_test = sox.core.soxi(f"{folder}/{file}", "D")
            if sox.file_info.num_samples(f"{folder}/{file}") > max_samples:
                max_samples = sox.file_info.num_samples(f"{folder}/{file}")
            if one_shots.index(file) == 0:
                sample_rate = sox.file_info.sample_rate(f"{folder}/{file}")
                if sample_rate < 44100:
                    sample_rate = 44100
                channels = sox.file_info.channels(f"{folder}/{file}")
            if one_shots.index(file) >= 127:
                print(f"Folder exceeds 128 files. {file} will not be included.")
                one_shots.remove(file)
        except sox.core.SoxiError:
            one_shots.remove(file)
    os.mkdir(f"{folder}_temp")
    for file in one_shots:
        samples_to_add = max_samples - sox.file_info.num_samples(f"{folder}/{file}")
        tfm = sox.Transformer()
        if samples_to_add > 0:
            tfm.pad(0.0, samples_to_add / sample_rate)
        tfm.norm(0.0)
        tfm.build(f"{folder}/{file}", f"{folder}_temp/{file}")
        concat_files.append(file)
    out_filename = f"{folder}_{len(concat_files)}slices.wav"
    combine_files(f"{folder}_temp", concat_files, out_filename, sample_rate, channels, bit_depth)
    for file in all_files:
        try:
            os.remove(f"{folder}_temp/{file}")
        except FileNotFoundError:
            continue
    os.rmdir(f"{folder}_temp")