...
file_train = os.path.join(rootDir,"data/train/rg_train_"+modle_date+"_"+aiscene+".train") 
with open(file_train, 'r')as fp:
	textlist = fp.readlines()
	for text in textlist:
		if ":" in text:
			L4ID = text.split(":")[-2]
			Msg = text.split(":")[-1]
			if query_start == Msg.strip("\n"):
				print("Msg is in train:",Msg)
...

# -*- coding:utf-8 -*-
__author__ = 'ShawDa'

import glob

xmls = glob.glob('xml_files/*.xml')
for one_xml in xmls:
  print(one_xml)
  f = open(one_xml, 'r+', encoding='utf-8')
  all_the_lines = f.readlines()
  f.seek(0)
  f.truncate()
  for line in all_the_lines:
    line = line.replace('dog', 'pig')
    line = line.replace('cat', 'bike')
    f.write(line)
  f.close()