Regular Expression "+" perform wrong repeat

[tld5yj]

BPO	14510
Nosy	@ezio-melotti
Files	CheckInconsistency.py: Just used to check symbol inconsistency in two strings

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/ezio-melotti'
closed_at = <Date 2012-04-06.01:41:04.870>
created_at = <Date 2012-04-05.13:47:46.780>
labels = ['expert-regex', 'type-bug', 'invalid']
title = 'Regular Expression "+" perform wrong repeat'
updated_at = <Date 2012-04-06.13:46:20.661>
user = 'https://bugs.python.org/tld5yj'

bugs.python.org fields:

activity = <Date 2012-04-06.13:46:20.661>
actor = 'tld5yj'
assignee = 'ezio.melotti'
closed = True
closed_date = <Date 2012-04-06.01:41:04.870>
closer = 'ezio.melotti'
components = ['Regular Expressions']
creation = <Date 2012-04-05.13:47:46.780>
creator = 'tld5yj'
dependencies = []
files = ['25136']
hgrepos = []
issue_num = 14510
keywords = []
message_count = 5.0
messages = ['157588', '157600', '157632', '157664', '157665']
nosy_count = 3.0
nosy_names = ['ezio.melotti', 'mrabarnett', 'tld5yj']
pr_nums = []
priority = 'normal'
resolution = 'not a bug'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue14510'
versions = ['Python 3.2']

[tld5yj]

Regular expression perform wrong result, I use regular expression r'(\$.)+' try to match "$B$b" or something like that, but the script only give back "$b", r'(\$.){1,}', r'(\$.){2}' performed the same, you can take the file I attached for reference and run it, I try to solve it myself but failed, now I must use other ways to realize my aim, so appreciate for you help, thank you!

[mrabarnett]

If a capture group is repeated, as in r'(\$.)+', only its last match is returned.

[ezio-melotti]

>>> re.findall(r'((?:\$.)+)', 'This $b$B is also a variable, but it\'s not $B$b')
['$b$B', '$B$b']

[tld5yj]

Well, maybe I had never understood this though I use RE oftenly, this is the first time I met this and in my mind capture should not perform like this, thank you very much!

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发件人： Matthew Barnett <report@bugs.python.org>
收件人： tld5yj@yahoo.com.cn
发送日期： 2012年4月6日, 星期五, 上午 12:08
主题: [bpo-14510] Regular Expression "+" perform wrong repeat

Matthew Barnett <python@mrabarnett.plus.com> added the comment:

If a capture group is repeated, as in r'(\$.)+', only its last match is returned.

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Python tracker <report@bugs.python.org>
<http://bugs.python.org/issue14510\>

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[tld5yj]

If that was caused by capture, I think I should learn and use it from start because it gave a result I didn't want but in the way I want, thank you very much, I will be more careful next time, thank you!

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发件人： Ezio Melotti <report@bugs.python.org>
收件人： tld5yj@yahoo.com.cn
发送日期： 2012年4月6日, 星期五, 上午 9:41
主题: [bpo-14510] Regular Expression "+" perform wrong repeat

Ezio Melotti <ezio.melotti@gmail.com> added the comment:

['$b$B', '$B$b']

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assignee:  -> ezio.melotti
resolution:  -> invalid
stage:  -> committed/rejected
status: open -> closed

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Python tracker <report@bugs.python.org>
<http://bugs.python.org/issue14510\>

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