python NameError: name 'file' is not defined

import sys
import time
import os

poem='''\
测试读写文件
'''
print(os.getcwd())
f=file(os.getcwd()+'/python.txt','w')
f.write(poem)
f.close()


C:\Users\Administrator\Desktop
Traceback (most recent call last):
  File "C:\Users\Administrator\Desktop\pythonTwo.py", line 9, in <module>
    f=file(os.getcwd()+'/python.txt','w')
NameError: name 'file' is not defined
[Finished in 0.2s with exit code 1]


解决方法：file()改为open()