Beginner question - How to effectively pass a large list

[Delaney, Timothy C (Timothy)]

> From: J.R.

[snip the results of some pretty good investigation and reasoning]

> I think we could eliminate such accumulation effect by 
> changing the function
> as follow:
> >>> def f(d=[]):
>         d = d+[0]
>         print d

The above would work in this case, but is not the canonical way.

def f (d=None):

    if d is None:
        d = []

    d.append(0)
    print d

i.e. use None as a sentinel, and if no parameter is passed create a list to use. In particular, your version uses a different interface to perform the append - d.__add__(list) rather than d.append(int).

Tim Delaney