Python Tricks #23 - is vs ==

# "is" vs "=="

>>> a = [1, 2, 3]
>>> b = a

>>> a is b
True
>>> a == b
True

>>> c = list(a)

>>> a == c
True
>>> a is c
False

# • "is" expressions evaluate to True if two 
#   variables point to the same object

# • "==" evaluates to True if the objects 
#   referred to by the variables are equal