python - replacing all regex matches in single line -

i have dynamic regexp in don't know in advance how many groups has replace matches xml tags

example

re.sub("(this).*(string)","this string",'<markup>\anygroup</markup>') >> "<markup>this</markup> <markup>string</markup>" 

is possible in single line?

for constant regexp in example, do

re.sub("(this)(.*)(string)",        r'<markup>\1</markup>\2<markup>\3</markup>',        text) 

note need enclose .* in parentheses if don't want lose it.

now if don't know regexp looks like, it's more difficult, should doable.

pattern = "(this)(.*)(string)" re.sub(pattern,        lambda m: ''.join('<markup>%s</markup>' % s if n % 2 == 0                          else s n, s in enumerate(m.groups())),        text) 

if first thing matched pattern doesn't have marked up, use instead, first group optionally matching prefix text should left alone:

pattern = "()(this)(.*)(string)" re.sub(pattern,        lambda m: ''.join('<markup>%s</markup>' % s if n % 2 == 1                          else s n, s in enumerate(m.groups())),        text) 

you idea.

if regexps complicated , you're not sure can make part of group, every second group needs marked up, might smarter more complicated function:

pattern = "(this).*(string)" def replacement(m):     s = m.group()     n_groups = len(m.groups())     # assume groups not overlap , listed left-to-right     in range(n_groups, 0, -1):         lo, hi = m.span(i)         s = s[:lo] + '<markup>' + s[lo:hi] + '</markup>' + s[hi:]     return s re.sub(pattern, replacement, text) 

if need handle overlapping groups, you're on own, should doable.