How to re replace string variables?

[Hans Nowak]

On 7 Sep 99, at 14:31, Joel Burton wrote:

> I'm an experienced perl programmer, but new to Python. I'm trying to
> convert over a script that searches a text file, replacing all instances
> of variables (in this case, flagged by a leading $) with the string
> variable with that name.
> 
> In perl, I would do this by
>     s/\$([A-za-z]\w*)/${$1}/g
> 
> which finds every instances of $xxx and replaces it with the scalar
> variable $xxx.
> 
> However, I can't figure out how to do this in Python. Can I refer to a
> variable by referenced name?
> 
> I could switch this so that all the variables are in a dictionary, so
> P['one'] = 'uno' P['two'] = 'dos', etc.
> 
> With a string that looks like: "Is $one the same as $two"?
> 
> But I get bogged down with errors when I try things like
> 
> re.sub("(\$\w+)",P['\\1'], string)
> 
> Because re module, when it gets the repl string/subroutine, hasn't
> resolved what \1 is.
> 
> Any help would be very appreciated. Thanks!

I happen to have a snippet that might do what you want:

http://tor.dhs.org/~zephyrfalcon/snippets/source/111.py

(Disclaimer: Didn't use it myself, though.)

--Hans Nowak (zephyrfalcon at hvision.nl)
Homepage: http://fly.to/zephyrfalcon
Python Snippets: http://www.hvision.nl/~ivnowa/snippets/
The Purple Kookaburra Forum: http://www.delphi.com/kookaburra/