[Tutor] What exactly is [::-1]?
alan.gauld at btinternet.com
Thu Jul 26 10:04:05 CEST 2007
"Dick Moores" <rdm at rcblue.com> wrote
>>Not sure why it didn't help you Dick, but it led me to:
> Alan, I don't see an explanation of [::-1] anywhere in those 3
> There needs to be a clear description and better examples somewhere
> in the docs, IMO.
I agree the explanation is 'terse' but it does explain that the syntax
is S[i:j:k] and that any/all of the values can be ommitted and what
defaults are. It also explains the significance of -1 as a value.
So [::-1] is simply i, j taking defaults and -1 for k
So its equivalent to S[0:len(S):-1]
But I agree there could be a few more examples of the use of
the k element.
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