list reversal error

[John Gordon]

In <8b3d06eb-0027-4396-bdf8-fee0cc9ff771 at googlegroups.com> vlyamtsev at gmail.com writes:

> i have list of strings "data" and i am trying to build reverse list data1
> data1 = []
> for i in range(len(data)):
>    j = len(data) - i
>    data1.append(data[j])

> but i have the following error:
> data1.append(data[j])
> IndexError: list index out of range
>  
> am i doing it wrong?
> Thanks

Python lists are zero-indexed, meaning a list of five items will have
indexes 0 to 4.

The first time through your loop, i is 0, so

    j = len(data) - i 

evaluates to

    j = len(data)

which would yield 5 for a five-element list, but the last actual element
is in data[4].

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"