import os

#
# def OperateFile(path, old_content, new_content):
#     with open(path) as f1, \
#             open(path+'.bak', mode='w') as f2:
#         for line in f1:
#             l1 = line.replace(old_content, new_content)
#             f2.write(l1)
#         os.remove(path)
#         os.rename(path+'.bak', path)
#
#
# OperateFile('test.txt', 'luhu', 'LUHU')
print('\d\t')



