In Python, is and is not operators are called identity operators. Each object in computer's memory is assigned a unique identification number (id) by Python interpreter. Identity operators check if id() of two objects is same. 'is' operator returns false of id() values are different and true if they are same.
>>> a=10 >>> b=a >>> id(a), id(b) (490067904, 490067904) >>> a is b True >>> a=10 >>> b=20 >>> id(a), id(b) (490067904, 490068064) >>> a is b False