Why does “if foo:” follow the branch even if the function foo returns False?

Question

def foo(a):
    print(\"I\'m foo\")
    return False


if foo:
    print(\"OK\")
else:
    print(\"KO\")

I run it and it returns OK. I know, I should h

Answer 1

In this case your code is same as

if foo != None:
    print("OK")
else:
    print("KO")

Result is

"OK"

because foo actually exists.