johnny <[EMAIL PROTECTED]> wrote: > I need to get the content inside the bracket.
> eg. some characters before bracket (3.12345). > I need to get whatever inside the (), in this case 3.12345. > How do you do this with python regular expression? I'm going to presume that you mean something like: I want to extract floating point numerics from parentheses embedded in other, arbitrary, text. Something like: >>> given='adfasdfafd(3.14159265)asdfasdfadsfasf' >>> import re >>> mymatch = re.search(r'\(([0-9.]+)\)', given).groups()[0] >>> mymatch '3.14159265' >>> Of course, as with any time you're contemplating the use of regular expressions, there are lots of questions to consider about the exact requirements here. What if there are more than such pattern? Do you only want the first match per line (or other string)? (That's all my example will give you). What if there are no matches? My example will raise an AttributeError (since the re.search will return the "None" object rather than a match object; and naturally the None object has no ".groups()' method. The following might work better: >>> mymatches = re.findall(r'\(([0-9.]+)\)', given).groups()[0] >>> if len(mymatches): >>> ... ... and, of couse, you might be better with a compiled regexp if you're going to repeast the search on many strings: num_extractor = re.compile(r'\(([0-9.]+)\)') for line in myfile: for num in num_extractor(line): pass # do whatever with all these numbers -- Jim Dennis, Starshine: Signed, Sealed, Delivered -- http://mail.python.org/mailman/listinfo/python-list