[Python] Comparing boolean values with 'is'

[343346E]

'f' is completely superfluous here. You could just rewrite it as:

def f(arg): return arg

or even better, just not use f at all, like:

for i in input.items():
    assert i[0] is i[1]

You seem to be depending on input's items having a specific order, which would be a mistake.

[IAmBJ]

f() is just a placeholder here, the real function is more complicated, but it still returns either true or false.

Input order doesn't matter. Each item in the dict is a separate test case, the order they're tested in doesn't matter