Can someone explain to me why it returns them in binaries?

Question

def convert(num):
if num == 0:
return 0
else:
return (num % 2 + 10 * convert(num // 2))
a = int(input())
print(convert(a))

Answer 1

Recursive base transformation is not a easy topic, you better try to calculate it by hand and write it down on a paper.

Lastly, the result is only resemble a binary by an integer, not a true binary.

Answer 2

This is code for converting a integer to binary equalent.
ex:
2 => 0 + 10*( 1+10*(0) ) = 10
3 => 1 + 10*( 1+10*(0) ) = 11