regex question

Alexei Zankevich zancudero at gmail.com
Tue Aug 5 14:06:08 CEST 2008


No, there is a bad way - because of the example doesn't solve arbitrary
amount of <number>.<number>.. blocks.
But the python regexp engine supports for lookahead (?=pattern) and
lookbehind (?<=pattern).
In those cases patterns are not included into the replaced sequence of
characters:
>>> re.sub('(?<=\d)\.(?=\d)', '', '1234.324 abc.100.abc abc.abc')
'1234324 abc.100.abc abc.abc'

Alexey

On Tue, Aug 5, 2008 at 2:10 PM, Marc 'BlackJack' Rintsch <bj_666 at gmx.net>wrote:

> On Tue, 05 Aug 2008 11:39:36 +0100, Fred Mangusta wrote:
>
> > In other words I'd like to replace all the instances of a '.' character
> > with something (say nothing at all) when the '.' is representing a
> > decimal separator. E.g.
> >
> > 500.675  ---->       500675
> >
> > but also
> >
> > 1.000.456.344 ----> 1000456344
> >
> > I don't care about the fact the the resulting number is difficult to
> > read: as long as it remains a series of digits it's ok: the important
> > thing is to get rid of the period, because I want to keep it only where
> > it marks the end of a sentence.
> >
> > I was trying to do like this
> >
> > s=re.sub("[(\d+)(\.)(\d+)]","... ",s)
> >
> > but I don't know much about regular expressions, and don't know how to
> > get the two groups of numbers and join them in the sub. Moreover doing
> > like this I only match things like "345.000" and not "1.000.000".
> >
> > What's the correct approach?
>
> In [13]: re.sub(r'(\d)\.(\d)', r'\1\2', '1.000.456.344')
> Out[13]: '1000456344'
>
>
> Ciao,
>         Marc 'BlackJack' Rintsch
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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