Python 如何测试正则表达式匹配
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/4742662/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
how to test for a regex match
提问by jml
I have a string. Let's call it 'test'. I want to test a match for this string, but only using the backref of a regex.
我有一个字符串。我们称之为“测试”。我想测试这个字符串的匹配，但只使用正则表达式的 backref。
Can I do something like this:
我可以做这样的事情：
import re
进口重新
for line in f.readlines():
if '<a href' in line:
if re.match('<a href="(.*)">', line) == 'test':
print 'matched!'
? This of course, doesn't seem to work, but I would think that I might be close? Basically the question is how can I get re to return only the backref for comparison?
? 这当然似乎行不通，但我认为我可能会接近？基本上问题是我怎样才能让 re 只返回 backref 进行比较？
采纳答案by mouad
re.matchmatches only at the beginningof the string.
def url_match(line, url):
match = re.match(r'<a href="(?P<url>[^"]*?)"', line)
return match and match.groupdict()['url'] == url:
example usage:
用法示例：
>>> url_match('<a href="test">', 'test')
True
>>> url_match('<a href="test">', 'te')
False
>>> url_match('this is a <a href="test">', 'test')
False
If the pattern could occur anywhere in the line, use re.search.
如果该模式可能出现在行中的任何位置，请使用re.search.
def url_search(line, url):
match = re.search(r'<a href="(?P<url>[^"]*?)"', line)
return match and match.groupdict()['url'] == url:
example usage:
用法示例：
>>> url_search('<a href="test">', 'test')
True
>>> url_search('<a href="test">', 'te')
False
>>> url_search('this is a <a href="test">', 'test')
True
N.B : If you are trying to parsing HTML using a regex, read RegEx match open tags except XHTML self-contained tagsbefore going any further.
注意：如果您尝试使用正则表达式解析 HTML，请在继续之前阅读RegEx 匹配打开的标签（XHTML 自包含标签除外）。
