python - 从字符串中获取子字符串的正则表达式

Question

考虑我有一个字符串如下，

\n this is a paragraph. please ignore  \n this is a only for testing. please ignore \n

我有一个搜索词为 "only for testing" .我想得到包含 "only for testing" 的句子与在 \n搜索词驻留。
在这种情况下，输出将是 this is a only for testing. please ignore .

如果我给 paragraph作为搜索词，我应该得到输出

this is a paragraph. please ignore

我试过了

test_str = "\\n this is a paragraph. please ignore  \\n this is a only for testing. please ignore \\n"
pattern = re.compile("\\\\n(.+?)\\\\n")
match = pattern.findall(test_str)

但没有按预期工作

Answer 1

您可以使用没有正则表达式的解决方案:

result = [sent for sent in test_str.split("\\n") if 'only for testing' in sent]

见 Python demo

详情

test_str.split("\\n") - 按 \n 拆分文本

if 'only for testing' in sent - 只保留包含 only for testing 的项目(对于不区分大小写的比较，使用 if 'only for testing' in sent.lower() )