Is there a difference between `==` and `is` in Python?

There is a simple rule of thumb to tell you when to use == or is.

  • == is for value equality. Use it when you would like to know if two objects have the same value.
  • is is for reference equality. Use it when you would like to know if two references refer to the same object.
>>> a = 500
>>> b = 500
>>> a == b
True
>>> a is b
False

 

 

注: 判断None的只能用xxx is None来做

 

ref: http://stackoverflow.com/questions/132988/is-there-a-difference-between-and-is-in-python

https://segmentfault.com/q/1010000000150947

posted @ 2016-12-27 12:28  圆旭  阅读(240)  评论(0编辑  收藏  举报