list reversal error
John Gordon
gordon at panix.com
Thu Mar 3 18:08:15 EST 2016
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"
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