How can I repeat a capturing group one or more time and extract matches

Question

Is it possibile with one regex to validate this string and extract all names :

Input :

daz.Da zD.{Azd} .{AZDza}; D
name:{franck}{steve}{louis}
zefzef{z'f'z} fze fzef zef

ouptut :

[0] "franck"
[1] "steve"
[2] "louis"

Here is what I got : name:(?:{(.*?)}) but I don't know how to repeat (one or more) this expression (?:{(.*?)}) to extract all name after name:.

I don't want to use regex python package that supports repeated capturing groups.

Possible duplicate of [Capturing repeating subpatterns in Python regex](http://stackoverflow.com/questions/9764930/capturing-repeating-subpatterns-in-python-regex) — Remi Guan, Nov 21 '15 at 12:20

bobble bubble · Accepted Answer · 2015-11-21T12:37:00.650

3

You can chain the matches by using the \G anchor with Python regex package.

It matches at the position where each search started/continued

(?:name:|\G(?!^)){([^}]+)}

(?:name:|\G(?!^)) first part: Match name: literally |\G or continue where the last match ended, (?!^) but not at start.
{([^}]+)} second part: Capture non} inside {...} to $1 glued to successfull previous match.

Use with regex.findall

See demo at regex101

edited Nov 21 '15 at 12:37

answered Nov 21 '15 at 12:20

bobble bubble

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Thank you! This is what I wanted! :) – Louis Barranqueiro Nov 21 '15 at 12:34
1

With the regex package you can do much simpler, since it is able to store results of a repeated capture group. You can use this simple pattern with the `search` method: `name:(?:{([^}]+)})+` and use `m.captures(1)` to obtain the list of results. – Casimir et Hippolyte Nov 21 '15 at 14:17

Avinash Raj · Answer 2 · 2015-11-21T12:25:29.260

Not with a single regex but you may do like this,

>>> s = '''daz.Da zD.{Azd} .{AZDza}; D
name:{franck}{steve}{louis}
zefzef{z'f'z} fze fzef zef'''
>>> [j for i in re.findall(r'(?m)^name:(.*)', s) for j in re.findall(r'\{([^}]*)\}', i)]
['franck', 'steve', 'louis']

This would print all the names present inside the curly barces from the line which starts with name:

or

Use startswith

>>> s = '''daz.Da zD.{Azd} .{AZDza}; D
name:{franck}{steve}{louis}
zefzef{z'f'z} fze fzef zef'''.splitlines()
>>> [j for line in s  for j in re.findall(r'\{([^}]*)\}', line) if line.startswith('name')]
['franck', 'steve', 'louis']

How can I repeat a capturing group one or more time and extract matches

2 Answers2