hash( (-2,2) ) == hash( (2,-2) ) returns True (Python)

Question

So, this is fun - Python's hash notoriously returns True on hash(-1) == hash(-2), as discussed elsewhere, but what about this?

>>> hash( (-2,2) ) == hash( (2,-2) )
True

Is this a feature?

Some other quick experiments:

>>>(-2,2) == (2,-2)
False
>>>hash( (-1,) ) == hash( (-2,) )
True
>>>hash( (-1,-2) ) == hash( (-2,-1) )
True
>>>hash( (-2.01,2.01) ) == hash( (2.01,-2.01) )
False
>>>hash( (-1,1) ) == hash( (1,-1) ) 
False

Answer 1

It's not a feature; it's a coincidence. Hash collisions occur.

Python's int hashing is really dumb and its tuple hashing is usually okay.

Python's dict implementation is meant to kick serious butt with bad hashes, so it doesn't matter too much.