| msg91393 - (view) |
Author: Phillip M. Feldman (Phillip.M.Feldman@gmail.com) |
Date: 2009-08-07 06:00 |
| As per the Python documentation, the following regular expression should produce a list containing the strings '6.7', 7.33', and '9': re.findall('(-?\d+[.]\d+)|(-?\d+[.]?) |
(-?[.]\d+)', 'asdf6.7jjjj7.33ff9') Instead, it generates a list of tuples. Either the documentation should be changed to make it consistent with what re.findall is actually doing, or, better yet, re.findall should be fixed. |
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| msg91401 - (view) |
Author: Alexey Shamrin (ash) |
Date: 2009-08-07 12:23 |
| You've made three groups with parentheses. Just drop them: >>> re.findall('-?\d+[.]\d+|-?\d+[.]? |
-?[.]\d+', 'asdf6.7jjjj7.33ff9') ['6.7', '7.33', '9'] Everything is according to documentation: "If one or more groups are present in the pattern, return a list of groups; this will be a list of tuples if the pattern has more than one group." http://docs.python.org/library/re.html#re.findall I would suggest to close this bug. |
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| msg91411 - (view) |
Author: Phillip M. Feldman (Phillip.M.Feldman@gmail.com) |
Date: 2009-08-07 19:46 |
| You are right-- the documentation does say this, although it took me a while to understand what it means. Thanks! It seems as though there's a flaw in the design here, because there should be some mechanism for grouping elements of a regular expression without having findall treat these as groups for purposes of packaging the output. If someone really wants to get lists of tuples out of findall, then it might make sense to input a tuple of strings instead of a single string. Phillip Alexey Shamrin wrote: > Alexey Shamrin <shamrin@gmail.com> added the comment: > > You've made three groups with parentheses. Just drop them: > > >>>> re.findall('-?\d+[.]\d+|-?\d+[.]? |
-?[.]\d+', 'asdf6.7jjjj7.33ff9') >>>> > ['6.7', '7.33', '9'] > > Everything is according to documentation: "If one or more groups are > present in the pattern, return a list of groups; this will be a list of > tuples if the pattern has more than one group." > > http://docs.python.org/library/re.html#re.findall > > I would suggest to close this bug. > > ---------- > nosy: +ash > > _______________________________________ > Python tracker <report@bugs.python.org> > <http://bugs.python.org/issue6663> > _______________________________________ > > |
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| msg91415 - (view) |
Author: Matthew Barnett (mrabarnett) *  |
Date: 2009-08-07 23:54 |
| In a regular expression (...) will group and capture, whereas (?:...) will only group and not capture. |
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