How to make a function return a value

savecancel

Exactly what seems to not be working? It is printing out what you ask it to. If you want it to return values for further use and not just print them, that is a little different - you will have to use the return statement.

To complement @kcrisman's answer: the code you gave looks like a "debugging" version, with the print statements.

I suppose you would want to comment out the print statements and make the function return the result.

def euclide(a,b):
    r=a%b
    # print (a,b,r)
    while r !=0:
        a=b; b=r
        r=a%b
        # print (a,b,r)
    return b

Then you would get:

sage: euclide(12,5)
1

Or you could introduce an extra (optional) argument to your function to decide whether to print steps.

def euclide(a,b,verbose=False):
    r=a%b
    if verbose:
        print (a,b,r)
    while r !=0:
        a=b; b=r
        r=a%b
        if verbose:
            print (a,b,r)
    return b

Then you could do:

sage: euclide(12,5) 
1
sage: euclide(12,5,verbose=True)
(12, 5, 2)
(5, 2, 1)
(2, 1, 0)
1