Trimming a video using FFMPEG using Python

ffmpegTrim.py

import os

def runBash(command):
	os.system(command)

def crop(start,end,input,output):
	str = "ffmpeg -i " + input + " -ss  " + start + " -to " + end + " -c copy " + output
	print str
	runBash(str)

crop("00:07:09","00:09:12","ch1.mp4","level00.mp4")
crop("00:09:12","00:14:48","ch1.mp4","level01.mp4")
crop("00:11:48","00:14:13","ch1.mp4","level02.mp4")
crop("00:14:13","00:15:43","ch1.mp4","level03.mp4")
crop("00:15:43","00:18:27","ch1.mp4","level04.mp4")
crop("00:18:27","00:22:55","ch1.mp4","level05.mp4")
crop("00:22:55","00:29:54","ch1.mp4","level06.mp4")
crop("00:29:54","00:31:04","ch1.mp4","level07.mp4")
crop("00:31:04","00:33:10","ch1.mp4","level08.mp4")
crop("00:33:10","00:38:13","ch1.mp4","level09.mp4")
crop("00:38:13","00:42:17 ","ch1.mp4","level1018.mp4")
crop("00:42:17","00:42:52","ch1.mp4","level19.mp4")

Its not working
Simply nothing is showing

It is working perfectly. Have you added ffmpeg to your User Path?

Edit: Tested on Windows OS

It will work, just in case it doesnt, install ffmpeg.
On debian systems you can install it using apt-get install ffmpeg.