Pycharm错误提示

#coding:utf-8


def test_file():
    f=codecs.open('C:\Users\john\Desktop\11.txt','r+',encoding='utf-8')
    # content=f.read()
    f.write(u"测试information")
    f.close()

test_file()

　　错误提示：

"D:\Program Files (x86)\Python 2.7.11\python.exe" "D:/Program Files (x86)/Python 2.7.11/Lib/site-packages/Card/algorithm/string_test.py"
Traceback (most recent call last):
  File "D:/Program Files (x86)/Python 2.7.11/Lib/site-packages/Card/algorithm/string_test.py", line 100, in <module>
    test_file()
  File "D:/Program Files (x86)/Python 2.7.11/Lib/site-packages/Card/algorithm/string_test.py", line 80, in test_file
    f=codecs.open('C:\Users\john\Desktop\11.txt','r+',encoding='utf-8')
  File "D:\Program Files (x86)\Python 2.7.11\lib\codecs.py", line 896, in open
    file = __builtin__.open(filename, mode, buffering)
IOError: [Errno 22] invalid mode ('r+b') or filename: 'C:\\Users\\john\\Desktop\t.txt'

　　也是被这编译器坑哭了，好几次的编译结果压根就不是当前的。

　　修改后的错误代码:

　　

f=codecs.open('C:\\Users\\john\Desktop\\11.txt','r+',encoding='utf-8')

　　-----------------------------------------

　　python中‘\xx'编码格式为utf-8,\形成了字符转义，必须用\\,也可在字符串前加r,产生原始字符串即可。