Searching and replacing text ?

[Gabriel Genellina]

En Fri, 02 May 2008 15:51:42 -0300, Oltmans <rolf.oltmans at gmail.com>  
escribió:

> Hi,
>
> I'm new to Python (and admittedly not a very good programmer) and I've
> come across a scenario where I've to search and replace text in a
> file.
>
> For the sake of an example, I'm searching for every occurence of the
> text
> [[http://www.hotmail.com -> Hotmail]]
>
> I've to replace it with
> [http://www.hotmail.com Hotmail]
>
> I've come up with following scheme
> p=re.compile(r'\[\[')
> q=re.compile(r'->')
>
> p.sub('[',txt)
> q.sub('\b',txt)

Is it a constant text? Then use the replace method of string objects: no  
re is needed.

text = "This is [[http://www.hotmail.com -> Hotmail]] some text"
print text.replace("[[http://www.hotmail.com -> Hotmail]]",  
"[http://www.hotmail.com Hotmail]")
output: This is [http://www.hotmail.com Hotmail] some text

Or, do you want to find '[[' followed by some word followed by ' -> '  
followed by another word followed by ']]'?

r = re.compile(r'\[\[(.+?)\s*->\s*(.+?)\]\]')
print r.sub(r'[\1 \2]', text)
(same output as above)

() in the regular expression indicate groups, that you can reference as \1  
\2 in the replacement string.

-- 
Gabriel Genellina