Python student seeks help regex/strings

[John Machin]

On Apr 12, 2:30 pm, Petyr David <phyn... at gmail.com> wrote:
> I'm familiar with simple string substitutions in shell and perl:
>
> string= "I have 30 days to find it"
>
> echo $string | sed "s/\(.*\)\(30\)\(.*\)/\2/
>
> which will (if I did it right) leave 30
>
> and perl likewise.
>
> I'm having trouble figuring out how to do this in Python and it's not
> for lack of trying to find an example. It can't be this hard is it?

No, it isn't; there are examples in the docs (http://docs.python.org/
library/re.html#re.sub) and the HOWTO (http://docs.python.org/dev/
howto/regex.html#search-and-replace) ... how did you manage to avoid
finding them?

 >>> import re
 >>> strg = "yadda 30 blah"
 >>> re.sub(r"(.*)(30)(.*)", r"\2", strg)
 '30'