I'm not quite sure what your asking, but I'll give it a shot. You do not have to use enumerate, you can use other methods just as range(len(sequence)), but the reason you cannot asign a value is because a for loop iterates a sequence meaning when you do
for a in [1, 2, 3, 4, 5]: ... a is just a value pulled from the sequence iteration. just like i and number is a value pulled from the iteration in for i, number in enumerate(a): ... (That was worded badly :/ I apologise.) Danny Colligan wrote: > In the following code snippet, I attempt to assign 10 to every index in > the list a and fail because when I try to assign number to 10, number > is a deep copy of the ith index (is this statement correct?). > > >>> a = [1,2,3,4,5] > >>> for number in a: > ... number = 10 > ... > >>> a > [1, 2, 3, 4, 5] > > So, I have to resort to using enumerate to assign to the list: > > >>> for i, number in enumerate(a): > ... a[i] = 10 > ... > >>> a > [10, 10, 10, 10, 10] > > My question is, what was the motivation for returning a deep copy of > the value at the ith index inside a for loop instead of the value > itself? Also, is there any way to assign to a list in a for loop (with > as little code as used above) without using enumerate? > > Thanks, > > Danny -- http://mail.python.org/mailman/listinfo/python-list
