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

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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

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

标签：value   like   reference   pytho   com   tac   als   class   one   

原文地址：http://www.cnblogs.com/pinganzi/p/6225423.html