In Python, the (?P<group_name>…) syntax allows one to refer to the matched string through its name:
>>> import re
>>> match = re.search('(?P<name>.*) (?P<phone>.*)', 'John 123456')
>>> match.group('name')
'John'
What does "P" stand for? I could not find any hint in the official documentation.
I would love to get ideas about how to help my students remember this syntax. Knowing what "P" does stand for (or might stand for) would be useful.
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python
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Python Extension. From the Python Docs:
The solution chosen by the Perl developers was to use (?...) as the extension syntax. ? immediately after a parenthesis was a syntax error because the ? would have nothing to repeat, so this didn’t introduce any compatibility problems. The characters immediately after the ? indicate what extension is being used, so (?=foo) is one thing (a positive lookahead assertion) and (?:foo) is something else (a non-capturing group containing the subexpression foo).
Python supports several of Perl’s extensions and adds an extension syntax to Perl’s extension syntax.If the first character after the question mark is a P, you know that it’s an extension that’s specific to Python
Pattern! The group names a (sub)pattern for later use in the regex. See the documentation here for details about how such groups are used.
Source: Stackoverflow.com