仅 Python 正则表达式匹配空间
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Python regex match space only
提问by Dimitry
In python3, how do I match exactly whitespace character and not newline \n or tab \t?
在python3中，如何完全匹配空白字符而不是换行符\n或制表符\t？
I've seen the \s+[^\n]answer from Regex match space not \nanswer, but for the following example it does not work:
我已经看到Regex 匹配空间的\s+[^\n]答案 不是 \n答案，但对于以下示例，它不起作用：
a='rasd\nsa sd'
print(re.search(r'\s+[^ \n]',a))
Result is <_sre.SRE_Match object; span=(4, 6), match='\ns'>, which is the newline matched.
结果是<_sre.SRE_Match object; span=(4, 6), match='\ns'>，这是匹配的换行符。
回答by Resonance
No need for special groups. Just create a regex with a space character. The space character does not have any special meaning, it just means "match a space".
不需要特殊群体。只需创建一个带有空格字符的正则表达式。空格字符没有任何特殊含义，它只是表示“匹配一个空格”。
RE = re.compile(' +')
So for your case
所以对于你的情况
a='rasd\nsa sd'
print(re.search(' +', a))
would give
会给
<_sre.SRE_Match object; span=(7, 8), match=' '>
回答by Wiktor Stribi?ew
If you want to match 1 or more whitespace chars except the newline and a tab use
如果要匹配除换行符和制表符之外的 1 个或多个空白字符，请使用
r"[^\S\n\t]+"
The [^\S]matches any char that is not a non-whitespace = any char that is whitespace. However, since the character class is a negated one, when you add characters to it they are excluded from matching.
的[^\S]任何字符不是相匹配的非空白=任何炭是空格。但是，由于字符类是否定类，因此当您向其中添加字符时，它们会被排除在匹配之外。
import re
a='rasd\nsa sd'
print(re.findall(r'[^\S\n\t]+',a))
# => [' ']
Some more considerations: \smatches [ \t\n\r\f\v]if ASCII flag is used. So, if you plan to only match ASCII, you might as well use [ \r\f\v]to exclude the chars you want. If you need to work with Unicode strings, the solution above is a viable one.
更多注意事项：如果使用 ASCII 标志，则\s匹配[ \t\n\r\f\v]。因此，如果您打算只匹配 ASCII，您不妨使用[ \r\f\v]排除您想要的字符。如果您需要使用 Unicode 字符串，上面的解决方案是可行的。
