Reverse string-formatting (maybe?)

Dustan DustanGroups at gmail.com
Sun Oct 15 15:21:16 CEST 2006


Dustan wrote:
> Dustan wrote:
> > Tim Chase wrote:
> > > > My template outside of the '%s' characters contains only commas and
> > > > spaces, and within, neither commas nor spaces. Given that information,
> > > > is there any reason it might not work properly?
> > >
> > > Given this new (key) information along with the assumption that
> > > you're doing straight string replacement (not dictionary
> > > replacement of the form "%(key)s" or other non-string types such
> > > as "%05.2f"), then yes, a reversal is possible.  To make it more
> > > explicit, one would do something like
> > >
> > >  >>> template = '%s, %s, %s'
> > >  >>> values = ('Tom', 'Dick', 'Harry')
> > >  >>> formatted = template % values
> > >  >>> import re
> > >  >>> unformat_string = template.replace('%s', '([^, ]+)')
> > >  >>> unformatter = re.compile(unformat_string)
> > >  >>> extracted_values = unformatter.search(formatted).groups()
> > >
> > > using '[^, ]+' to mean "one or more characters that aren't a
> > > comma or a space".
> > >
> > > -tkc
> >
> > Thanks.
> >
> > One more thing (I forgot to mention this other situation earlier)
> > The %s characters are ints, and outside can be anything except int
> > characters. I do have one situation of '%s%s%s', but I can change it to
> > '%s', and change the output into the needed output, so that's not
> > important. Think something along the lines of "abckdaldj iweo%s
> > qwierxcnv !%sjd".
>
> That was written in haste. All the information is true. The question:
> I've already created a function to do this, using your original
> deformat function. Is there any way in which it might go wrong?

Again, haste. I used Peter's deformat function.




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