Python 正则表达式仅根据正则表达式替换段落中的特定行而不是整个文件

Question

s="""Paragraph 1
some text blah blah
blah blah
UNWANTED TEXT
some text
Paragraph END

UNWNTED TEXT

Paragraph 2
some text blah blah
blah blah
UNWNTED TEXT
Paragraph END"""

现在 python 代码 re.sub 只替换段落内的不需要的文本，保留段落外的不需要的文本

search_unwanted_only_inparagrap = re.findall('(?s)(?<=Paragraph)(.*?)(?=END)', text_file, flags = re.MULTILINE )
if search_unwanted_only_inparagrap:
    replace_only_insidepara = re.sub(r"UNWANTED TEXT+", " ", text_file)   #replace string substitue
    print (replace_only_insidepara)
else:
    print ("not found")

但是输出替换了整个文件中的所有 UNWANTED TEXT 实例

Paragraph 1
some text blah blah
blah blah

some text
Paragraph END



Paragraph 2
some text blah blah
blah blah

Paragraph END

但我希望这样

Paragraph 1
some text blah blah
blah blah

some text
Paragraph END

UNWNTED TEXT

Paragraph 2
some text blah blah
blah blah

Paragraph END

请帮忙。

Answer 1

您的演示输入应该更多 'minimal'。但是，我试图了解您的要求并尝试 re.split 有效：

import re

s = """Paragraph 1
some text blah blah
blah blah
UNWANTED TEXT
some text
Paragraph END

UNWANTED TEXT

Paragraph 2
some text blah blah
blah blah
UNWANTED TEXT
Paragraph END"""
reg_para = re.compile(r'(Paragraph\s+\d+.+?END)', re.DOTALL)
paras = reg_para.split(s)
for para in paras:
    if reg_para.match(para):
        para = re.sub(r"UNWANTED TEXT", " ", para)
        #  in case you want replace more words:
        #  of course you can use list of keywords some loops
        para = re.sub(r"Another WORD", " ", para)
        print(para)
    else:
        print(para)

输出：

Paragraph 1
some text blah blah
blah blah
 
some text
Paragraph END


UNWANTED TEXT


Paragraph 2
some text blah blah
blah blah
 
Paragraph END

Python 正则表达式仅根据正则表达式替换段落中的特定行而不是整个文件

Python regex to replace a Particular line in paragraphs as per regex only not whole file

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