I read article that talk bout tuple http://radar.oreilly.com/2014/10/python-tuples-immutable-but-potentially-changing.html
After reading this article I supposed that a tuple of non mutable object are not mutable and for this reason two tuple of same not mutable object in python is same
>>> a = (1, 2)
>>> b = (1, 2)
>>> a is b
False # but I expect True
But I dont understand why. We have
>>> a = (1,)
>>> b = (1, )
>>> a is b
True
Please someone can explain me in which case two tuple are same.