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Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example

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On 2014-07-10 16:37, fl wrote:
> Hi,
>
> This example is from the link:
>
> https://wiki.python.org/moin/RegularExpression
>
>
> I have thought about it quite a while without a clue yet. I notice that it uses
> double quote ", in contrast to ' which I see more often until now.
> It looks very complicated to me. Could you simplified it to a simple example?
>
>
> Thanks,
>
>
>
>
>
> import re
> split_up = re.split(r"(\(\([^)]+\)\))",
>                      "This is a ((test)) of the ((emergency broadcasting station.))")
>
>
> ...which produces:
>
>
> ["This is a ", "((test))", " of the ", "((emergency broadcasting station.))" ]
>
No it doesn't; you've omitted the final string.

The regex means:

(        Start of capture group.
\(       Literal "(".
\(       Literal "(".
[^)]+    One or more repeats of any character except a literal ")".
\)       Literal ")".
\)       Literal ")".
)        End of capture group.

.split returns a list of the parts of the string between the matches, 
and if, as in this example, there are capture groups, then those too:

[
'This is a ',                             # The part before the first
                                           # match.
'((test))',                               # The first match (group 1).
' of the ',                               # The part between the first
                                           # and second matches.
'((emergency broadcasting station.))',    # The second match.
''                                        # The part after the second
                                           # match.
]

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How to decipher :re.split(r"(\(\([^)]+\)\))" in the example fl <rxjwg98@gmail.com> - 2014-07-10 08:37 -0700
  Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example Peter Otten <__peter__@web.de> - 2014-07-10 18:49 +0200
  Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example MRAB <python@mrabarnett.plus.com> - 2014-07-10 18:01 +0100
  Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example Joel Goldstick <joel.goldstick@gmail.com> - 2014-07-10 13:05 -0400
  Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example Albert-Jan Roskam <fomcl@yahoo.com> - 2014-07-10 12:15 -0700
  Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example Cameron Simpson <cs@zip.com.au> - 2014-07-11 11:29 +1000
    Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example Roy Smith <roy@panix.com> - 2014-07-10 22:18 -0400
      Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example Tim Chase <python.list@tim.thechases.com> - 2014-07-10 21:37 -0500
        Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example Roy Smith <roy@panix.com> - 2014-07-10 23:33 -0400
          Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example Chris Angelico <rosuav@gmail.com> - 2014-07-11 14:31 +1000
          Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example alister <alister.nospam.ware@ntlworld.com> - 2014-07-11 08:00 +0000
          Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example Steven D'Aprano <steve@pearwood.info> - 2014-07-11 09:04 +0000
            Re: How to decipher :re.split(r"(\(\([^)]+\)\))" in the example Albert-Jan Roskam <fomcl@yahoo.com> - 2014-07-11 08:18 -0700

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