Recursion in Python (factorial function)

Question

I hope this is not too much of a stupid question, but why does the 'return 1' statement in this Python code return the factorial of a number? This also happens for 'return True', which I understand is equivalent to 'return 1'

def factorial(n):
    if n == 0:
        return 1
    else:
        return n * factorial(n-1)

return 1 does not return the factorial of a number all by itself; it depends on all the other values that have already been calculated in the recursion chain. — John Gordon
– John Gordon, Commented Jul 10, 2020 at 1:37

bhristov · Accepted Answer · 2020-07-10 01:33:39Z

1

n == 0 is the base case of the recursive function. Factorial of 0 is 1: reference

Once the base case returns 1, the statement return n * factorial(n-1) will have the form: return n * 1 and so on.

answered Jul 10, 2020 at 1:33

bhristov

3,2072 gold badges13 silver badges26 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

HichamDz38 · Accepted Answer · 2020-07-10 01:37:14Z

0

in python when you multiply a number by True it will operate like you are multiply by One, and when you multiply a number by False it will operate like when you multiply by Zero.

so this is why you get a factorial af a number even if you use:

return True

instead of

return 1

but if you will call factorial(0) you will get True instead of 1.

answered Jul 10, 2020 at 1:37

HichamDz38

1047 bronze badges

Collectives™ on Stack Overflow

Recursion in Python (factorial function)

2 Answers 2

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related