Regex validate PIN code

Description:

ATM machines allow 4 or 6 digit PIN codes and PIN codes cannot contain anything but exactly 4 digits or exactly 6 digits.

If the function is passed a valid PIN string, return true, else return false.

Examples (Input --> Output)

 

Solution:

1. 인자가 숫자인지 확인한다.

2. 인자의 길이가 4 혹은 6이라면 pin을 반환한다.

 

def validate_pin(pin):
    return pin.isdigit() and len(pin) in (4, 6)