python 中的 is 和 ==

• is 判断变量是否指向同一个对象
• == 判断变量引用的对象是否相等

in [2]: a=[1,2]

in [3]: b=a

in [4]: a == b
out[4]: true

in [5]: a is b
out[5]: true

in [6]: c = list(a)

in [7]: a == c
out[7]: true

in [8]: a is c
out[8]: false

in [9]: b is c
out[9]: false