#format python
#!/usr/bin/env python

import sys,os

Usage="""Source indentation converter tab to 4space

tabTo4Space.py filename
"""
try:
    fileName = sys.argv[1]
except:
    print Usage
    sys.exit()

wFile = open(fileName+'_','w')
for line in open(fileName,'r').readlines():
    newLine=line.replace('\t','    ')
    wFile.writelines(newLine)

try:
    os.rename(fileName+'_',fileName)
except:
    pass