what is the meaning of "return not" in this code?

Question

def is_even(x):
if x == 0:
return True
else:
return is_odd(x-1)

def is_odd(x):
return not is_even(x)

print(is_odd(17))
print(is_even(23))

output is
true
false why this false is coming?

Answer 1

There is no "return not". There is only return. "not" is a boolean operator that returns the boolean inverse of the value. In your code , is_odd fun returns " not is_even". Whatever is_even fun returns,"not" will reverse that. If is_even returns True, not will change it into False.

Answer 2

Because 23 is not even

Answer 3

Here's the same code with some suitable output, to help you understand the recursion:

https://code.sololearn.com/c3U3O9H1Q10e/?ref=app