Custom class object and "in" set operator

I'm using Python 3.6. Suppose that I'm trying to keep a unique set of tuples. I know I can use tuple in set and get back the correct result (the set contains the tuple or not).

s = set()  t1 = (1, 2)  t2 = (1, 2)  s.add(t1)  print(t2 in s) # True -- Great!  

Now, suppose I have a custom class that contains a tuple. I would like to define uniqueness for the custom class objects as uniqueness for the tuple. I did the following:

class TupleWrapper(object):        def __init__(self, t):          self.t = t # tuple        def __hash__(self):          return hash(self.t)      s = set()  t1 = TupleWrapper((1, 2))  s.add(t1)  t2 = TupleWrapper((1, 2))  print(t2 in s) # False -- WHY?  

I wrote my own __hash__() method that hashes the tuple. So why are the two TupleWrapper objects with the same tuple not found to be the same in the set? Do I need to override another method?

https://stackoverflow.com/questions/65820556/custom-class-object-and-in-set-operator January 21, 2021 at 10:57AM