This is an example of using pydub (http://pydub.com/) to trim a folder of songs from a given start time to end time specified in a text file.

pydub-trim-songs

import os
import pydub
pydub.AudioSegment.converter = '/usr/local/bin/ffmpeg'

songsDir = 'Original Songs'
trimmedDir = 'Trimmed Songs'
data = []

def trimSong(file, index):
    values = data[index].split(',')
    start = int(values[0]) * 1000
    end = int(values[1]) * 1000
    if not os.path.exists(trimmedDir):
        os.makedirs(trimmedDir)
    song = pydub.AudioSegment.from_mp3(os.path.join(songsDir, file))
    song = song[start:end].fade_in(2000).fade_out(2000)
    song = pydub.effects.normalize(song, 0.1)
    song.export(os.path.join(trimmedDir, file), format='mp3')

with open('data.txt') as f:
    for line in f:
        data.append(line.rstrip('\n'))

for subdir, dirs, files in os.walk(songsDir):
    index = -1
    for file in files:
        if file[-3:] != 'mp3':
            continue
        index += 1
        trimSong(file, index)