Question

When using regular expressions we generally, if not always use them to extract some kind of information. What I need is to replace the match value with some other value…

Right now I’m doing this…

def getExpandedText(pattern, text, replaceValue):     '''         One liner... really ugly but it's only used in here.     '''      return text.replace(text[text.find(re.findall(pattern, text)[0]):], replaceValue) + \             text[text.find(re.findall(pattern, text)[0]) + len(replaceValue):] 

so if I do sth like

>>> getExpandedText('aaa(...)bbb', 'hola aaaiiibbb como estas?', 'ooo') 'hola aaaooobbb como estas?' 

It changes the (…) with ‘ooo’.

Do you guys know whether with python regular expressions we can do this?

thanks a lot guys!!

Answer 1

sub (replacement, string[, count = 0]) 

sub returns the string obtained by replacing the leftmost non-overlapping occurrences of the RE in string by the replacement replacement. If the pattern isn’t found, string is returned unchanged.

    p = re.compile( '(blue|white|red)')     >>> p.sub( 'colour', 'blue socks and red shoes')     'colour socks and colour shoes'     >>> p.sub( 'colour', 'blue socks and red shoes', count=1)     'colour socks and red shoes'