使用python和regex在字符串中查找关键字

Question

我想在字符串中找到一个关键字，可以在字符串的开头，结尾或任何位置。

我从那样开始：

import re
my_keyword = "in ocean"
regex = r'[^|\,\s]?in ocean\,\s|[^|\,\s]?in ocean$'

应匹配：

in ocean there is big fish
in ocean
there is big fish in ocean
there is big fish in ocean but not in lakes
i like to swim in lake, in ocean too
in ocean, there is big fish

不匹配：

within ocean, you can find tresure
in oceania there is sirens
tintin ocean, the tresure hunter
do not dive within ocean

Answer 1

只需使用字边界：

regex = r'\bin ocean\b'

单词边界在\w个字符与\W字符之间，或\w与^或$之间匹配。

regex101 demo