Python格式化css文件的方法

import string, sysimport re, StringIOTAB=4def 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