正则表达式 - 字符串替换＆＃34;原样＆＃34;

Question

我正在尝试这样做：

单词test应在某些文字中找到，并替换为<strong>test</strong>。但问题是，Test也应该被捕获并替换为<strong>Test</strong>。

我试过了：

word = "someword"
text = "Someword and many words with someword"
pattern = re.compile(word, re.IGNORECASE)
result = pattern.sub('<strong>'+word+'</strong>',text)

但在这种情况下，Someword正在变为someword。我使用re错误了吗？

我想要<strong>Someword</strong> and many words with <strong>someword</strong>

Answer 1

您需要使用capturing group：

>>> import re
>>> word = "someword"
>>> text = "Someword and many words with someword"
>>> pattern = re.compile('(%s)' % word, re.IGNORECASE)
>>> pattern.sub(r'<strong>\1</strong>',text)
'<strong>Someword</strong> and many words with <strong>someword</strong>'

此处\1指的是第一个捕获的组，即括号内捕获的组。

另请参阅python re模块文档的Search and Replace部分。