Why does the while keep looping here? Can somebody explain?

Question

I have the below code to generate fibonacci series upto 'num'

def fibo(num,a=0,b=1):

    while b <= num:

        print(b)

        a, b = b, a+b

        fibo(num,a,b)

fibo(30)

And below is the Output. However if i use 'if' instead of 'while' in my code it works fine. But I wanted to know what is the problem with while here..

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Answer 1

This is because you are using both looping and recursion in your code. You need to use either one of them. e.g. if you wish to use loops:

def fibo(num,a=0,b=1):

    while b <= num:

        print(b)

        a, b = b, a+b

if you wish to use recursion:

def fibo(num,a=0,b=1):

    if b <= num:

        print(b)

        a, b = b, a+b

        fibo(num,a,b)