Why does Python ''in operator'' return 'True' for float 1.0 if only the int 1 is a list item in [1, 2.3, 'blabla']?

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In Python 3.8.5 Shell on Linux, I have a list named "mixedlist" (see below) that contains an integer, a floating point, and a string. As we can see, the integer 1 is contained in ''mixedlist'', whereas the number 1.1 is not. So far so good. What I don't understand: oddly, Python also returns 'True' for the floating point number 1.0 , even though the list only contains an integer 1. I assume this is not a bug but a feature. But if this is the expected behaviour, could someone point out why it makes sense?

>>> mixedlist = [1, 2.3, 'blabla']
>>> type(mixedlist[0])
<class 'int'>
>>> type(mixedlist[1])
<class 'float'>
>>> type(mixedlist[2])
<class 'str'>
>>> 1 in mixedlist
True
>>> 1.0 in mixedlist
True
>>> 1.1 in mixedlist
False
>>> 'blabla' in mixedlist
True
list python
1 Answers

This is because in does the == comparison, and 1 == 1.0 is True, while 1 == 1.1, 2.3 == 1.1, 'blabla' == 1.1 are all False.

https://docs.python.org/3/reference/expressions.html#in

For container types such as list, tuple, set, frozenset, dict, or collections.deque, the expression x in y is equivalent to any(x is e or x == e for e in y).

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