Question

Have an odd issue while using the active_directory module, which is amazing BTW… awesome wrapper.

Anyhow, I have a need to make sure that a username is unique… heres my function:

import active_directory

def creative_name(fname, lname, n=1):
    uname = fname[:n] + lname
    x = active_directory.find_user(uname)
    if x: creative_name(fname, lname, n+1)
    else: return uname

if __name__=='__main__':
    print creative_name("Sarah", "Smith")

it keeps coming up with None… I would expect it to return uname… or

fname[:n+1] + lname

its strange because if I run the function like this:

def creative_name(fname, lname, n=1):
    uname = fname[:n] + lname
    x = active_directory.find_user(uname)
    if x: creative_name(fname, lname, n+1)
    else: print uname

>>>
SaSmith
>>>

SaSmith is returned… why won’t it return the value?!?! print uname works but return uname returns None!

Please help!

Thanks all,

Randy

Answer 1

It wasn’t returning SaSmith because the recursive part wasn’t being returned, so if x was true the function returned None. Adding in one return should fix:

def creative_name(fname, lname, n=1):
    if n > len(fname): return None
    uname = fname[:n] + lname
    x = active_directory.find_user(uname)
    if x: return creative_name(fname, lname, n+1)
    else: return uname

.

Note: the first line prevents an infinite loop if active_directory.find_user(fname[:n]_lname) is True for every n.

I agree with @Randall that using a for loop is probably more readable, it returns None in the above case.