Python格式化css文件的方法

import string, sys
import re, StringIO
TAB=4
def format(ss):
 f = open (ss, "r")
 data = f.read()
 f.close()
 dlen = len(data)
 i = 0
 buf = StringIO.StringIO()
 start = 0
 while i < dlen:
 if data[i] == '{':
 buf.write(data[start:i] + ' { ')
 i = i + 1
 start = i
 elif data[i] == '}':
 last = string.strip(data[start:i])
 if last:
 buf.write(' '*TAB + last + ';')
 buf.write(' } ')
 i = i + 1
 start = i
 elif data[i] == ';':
 line = string.strip(data[start:i])
 buf.write(' '*TAB + line + '; ')
 i = i + 1
 start = i
 else:
 i = i + 1
 buf.write(data[start:i+1])
 return buf.getvalue()
if __name__ == '__main__':
 if len(sys.argv) == 1:
 print 'usage: cssformat.py filename'
 sys.exit()
 ret = format(sys.argv[1])
 print ret