On Sun, 31 May 2015 12:40:19 -0700, fl wrote:
> Hi,
>
> I have a string b='1234'. I run: br=reversed(b)
>
> I hope that I can print out '4321' by:
>
> for br in b
>
> but it complains:
> SyntaxError: invalid syntax
>
>
> My questions:
> 1. What use for reversed(). I do not find an example on web.
>
> 2. If reversed() is wrong the my purpose, what method can do it? i.e.
> '4321'
> out.
reversed returns an iterator, not a list, so it returns the reversed list
of elements one at a time. You can use list() or create a list from
reversed and then join the result:
$ python
Python 2.7.3 (default, Dec 18 2014, 19:10:20)
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> "".join(list(reversed("fred")))
'derf'
>>> "".join([x for x in reversed("fred")])
'derf'
So reversed can do it, but needs a little help
--
Denis McMahon, denismfmcma...@gmail.com
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