Schüle Daniel wrote: > Hello all, > > I didn't found more appropriate news group for > this question, please let me know if there is ng with > regular expression as its main topic > > I am trying to construct a case where a greedy and > non greedy operation produce different result. > I dont see the difference between 'a??b' and 'a?b' > As far I understand is that ? will first try to match a > (it's greedy) and only if it fails then it step back > and lets a unmatched. The other doesn't match a at first, > only if the pattern fails to match it steps back and match a. > > But don't they do eventually the same thing? > Can someone provide an example where 2 patterns yield > different results. > >>> target = "<h1>Sample String</h1>" >>> greedy = re.compile("<.+>") >>> nongreedy = re.compile("<.+?>") >>> m1 = greedy.match(target) >>> m2 = nongreedy.match(target) >>> m1.group(0) '<h1>Sample String</h1>' >>> m2.group(0) '<h1>' >>>
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