programm for greatest common divisor throw Valueexception

Question

Hello guys i need to write a programm which calculates the greatest common divisor of two numbers. The programm should throw an exception when 1 of the 2 input numbers are zero. But my code always throws this Exception now :( Hope you guys can help me :)

def ggt (a,b):
    if (b) or (a)==0:
        raise Exception(ValueError)
    else:
        return ggt(int(b), int(a%b))

print (ggt(25,14)

You call your function recursively, but there is no base case, so you always end up with a case where `a % b` is 0. — Thierry Lathuille, Jun 10 '21 at 11:51
When you use this Euclide algorithm by hand, when do you stop? This condition should be included in your code. — Thierry Lathuille, Jun 10 '21 at 11:55
BTW, `b or a == 0` [_doesn't_ do what you think it does](https://stackoverflow.com/questions/15112125/how-to-test-multiple-variables-against-a-single-value) — ForceBru, Jun 10 '21 at 11:57
Can you give me an example? When i changed the raise exception to return it worked but i need to do this with this raise Exception. — wqeeekendwrrar, Jun 10 '21 at 11:57

score 0 · Accepted Answer · answered Jun 10 '21 at 11:58

If I understand the question correctly, it can be done like this:

def ggt(a, b, first_time=True):
    if a * b == 0 and first_time:
        raise Exception(ValueError)  # the error occurs only if 0 on the first iteration
    elif b == 0:
        return a
    else:
        return ggt(b, a % b, False)

programm for greatest common divisor throw Valueexception

1 Answers1