collatz_recursion.py

def collatz(num):
    num = float(num)
    
    # base case
    if num == 1 :
        print(num)
        return

    # even
    if num%2 == 0 :
        print(num)
        return collatz(num/2)
    
    # odd
    elif num%2 != 0 :
        print(num)
        return collatz(3*num+1)