reallocating list in python

Question

Ok this is my problem. I am trying something like this:

for i in big_list:
   del glist[:]

   for j in range(0:val)
         glist.append(blah[j])

Idea is to reset list and reuse it for next set of data points. The problem is for some reason if the first list had 3 points. Therefore it used

glist[0]
glist[1]
glist[2]

The next list will for some reason continue from index 3 and store last 3 elements in those indexes

glist[0] = 4th elem of new list
glist[1] = 5th elem of new list
glist[2] = 6th elem of new list
glist[3] = 1st elem of new list
glist[4] = 2nd elem of new list
glist[5] = 3rd elem of new list

I am sure it is an issue with allocated space. But how can I achieve this del g_list[:] so the result is

glist[0] = 1st elem of new list
glist[1] = 2nd elem of new list
glist[2] = 3rd elem of new list
glist[3] = 4th elem of new list
glist[4] = 5th elem of new list
glist[5] = 6th elem of new list

Allocating variable from within loop is not an option. Any ideas?

Answer 1

Change del glist[:] to glist = []. You don't need to "reuse" or "reallocate" in Python, the garbagecollector will take care of that for you.

Also, you use 'i' as the loop variable in both loops. That's going to confuse you sooner or later. :)

Answer 2

you can try

glist=[]

Answer 3

del glist[:] works fine for clearing a list. You need to show us your exact code. As shown below, the behavior you're describing does not happen. The append after the del a[:] puts the item at index 0.

>>> a = [1,2,3]
>>> del a[:]
>>> a
[]
>>> a.append(4)
>>> a
[4]