List Behavior when inserting new items

[mensanator at aol.com]

On Jan 29, 1:10 pm, "Drew" <olso... at gmail.com> wrote:
> > What is your actual usecase?
>
> > diezThe issue is that I don't know how long the list will eventually be.
> Essentially I'm trying to use a 2D list to hold lines that I will
> eventually print to the screen. Blank elements in the list will be
> printed as spaces. I suppose every time I add an element, I could find
> the difference between the size of the list and the desired index and
> fill in the range between with " " values, however I just wanted to
> see if there was a more natural way in the language.

I would use DBR's suggestion to use a dictionary and only store
actual values. In this example, I'm making a histogram that only
ends up having results for 4,7,8,9,10 but I want the graph to show
the zero occurrences as well, so I just create them on the fly
when printing.

print
print 'tc factor of 2 distribution (* scale = 8)'
print
tchistkeys = tchist.keys()
tchistkeys.sort()
prev_key = 0
for i in tchistkeys:
    while prev_key<i:
        print '%3d (%3d)' % (prev_key,0)
        prev_key += 1
    print '%3d (%3d)' % (i,tchist[i]),
    hgraph = divmod(tchist[i],8)
    s = '*'*(hgraph[0])
    if hgraph[1]>0:
        s = s + '.'
    print s
    prev_key += 1

##    tc factor of 2 distribution (* scale = 8)
##
##      0 (  0)
##      1 (  0)
##      2 (  0)
##      3 (  0)
##      4 (  1) .
##      5 (  0)
##      6 (  0)
##      7 (112) **************
##      8 (219) ***************************.
##      9 ( 58) *******.
##     10 (110) *************.




>
> Thanks,
> Drew