nagy wrote: > Thanks, Kirk. > I considered the += as only a shorthand notation for the assignment > operator. > Since for lists + is simply a concatetation, I am not sure it x=x+[2] > is creating a brand > new list. Could you refer me to any documentation on this? > Thanks, > Nagy
My habit is to check the id. >>> x = [1,2] >>> id(x) -1209327188 >>> x += [4] >>> x [1,2,4] >>> id(x) -1209327188 >>> x = x + [6] >>> x [1,2,4,6] >>> id(x) -1209334664 So it looks as if x += [] modifies the list in place, while x = x + [] creates a new list. I am not sure if this is 100% guaranteed, as I have noticed in the past that id's can be reused under certain circumstances. Perhaps one of the resident gurus can comment. Frank Millman -- http://mail.python.org/mailman/listinfo/python-list