Message 253725 - Python tracker

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In-reply-to
Author	Pavel
Recipients	Pavel, docs@python
Date	2015年10月30日.10:07:26
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1446199646.71.0.249231376897.issue25517@psf.upfronthosting.co.za>

Content
The example advises ".[.](?!bat$).$" expression "to match filenames where the extension is not bat". But here is an example which passes such check: >>> re.match("(.)[.](?!bat$).$", "test.a.bat") <_sre.SRE_Match object at 0x7ff221996f30> To my mind use of negative lookbehind expressions (not covered so far in the HOWTO) is better: >>> re.match("(.)[.].(?<!.bat)$", "test.a.bat") >>>

Content

The example advises ".*[.](?!bat$).*$" expression "to match filenames where the extension is not bat". But here is an example which passes such check:
>>> re.match("(.*)[.](?!bat$).*$", "test.a.bat")
<_sre.SRE_Match object at 0x7ff221996f30>
To my mind use of negative lookbehind expressions (not covered so far in the HOWTO) is better:
>>> re.match("(.*)[.].*(?<!.bat)$", "test.a.bat")
>>>

History
Date	User	Action	Args
2015年10月30日 10:07:26	Pavel	set	recipients: + Pavel, docs@python
2015年10月30日 10:07:26	Pavel	set	messageid: <1446199646.71.0.249231376897.issue25517@psf.upfronthosting.co.za>
2015年10月30日 10:07:26	Pavel	link	issue25517 messages
2015年10月30日 10:07:26	Pavel	create

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