That's because of Python's duck typing – bool is a subclass of int.

print(False == 0 and True == 1) # Prints "True"

And since the description asks to return 0 when the numbers are equal and False is equivalent to 0, this is acceptable.

well, that'd be pretty anti-pythonic, tho... ;)

but false extending 0, if the expected answer is 0, that's still correct.

proof: this passes this fixed test: test.assert_equals(close_compare(5, 5), 0)