Q:

Python join (NameError: name 'join' is not defined)

Hello there is a function in my companies code that I don't understand. It does uses join without a preceding string object. Whenever I try to mimick this behaviour in my python shell I get the error:
 (NameError: name 'join' is not defined)

Which makes sense since join is not supposed to work that way
Here is the code:
from datetime import time
import math

def doit(reservations, operationFrom, operationTo):
    ret = [(operationFrom, operationTo, 0)]
    for res in reservations:
        ret = join(res, ret, sum)
    return ret

How come the join doesn't throw an error? Isn't join supposed to be used like so for example:
"fkasndfk".join(['x','y','z'])

A:

Either your company's code has a bug and the join call will produce an exception if it's ever executed (reservations could be empty!), or join is  defined somewhere else in the code.

