python 判断文件是否存在 os模块

# coding=utf-8

import os

if __name__ == '__main__':
    if os.path.isfile('test.txt'):
        print ("test.txt exist")
    else:
        print ("test.txt not exist")
    
    
    if os.path.isfile('hello.py'):
        print ("hello.py exist")
    else:

        print ("hello.py not exist")

http://docs.python.org/2/library/os.html