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Python regex findall

开发者 https://www.devze.com 2023-04-12 22:35 出处:网络
I am trying to extract all occurrences of tagged words from a string using regex in Python 2.7.2. Or simply, I want to extract every piece of text inside the [p][/p] tags.

I am trying to extract all occurrences of tagged words from a string using regex in Python 2.7.2. Or simply, I want to extract every piece of text inside the [p][/p] tags. Here is my attempt:

regex = ur"[\u005B1P\u005D.+?\u005B\u002FP\u005D]+?"
line = "President [P] Barack Obama [/P] met Microsoft founder [P] Bill Gates [/P], yesterday."
person = re.findall(pattern, line)

Printing person produces ['President [P]'开发者_C百科, '[/P]', '[P] Bill Gates [/P]']

What is the correct regex to get: ['[P] Barack Obama [/P]', '[P] Bill Gates [/p]'] or ['Barrack Obama', 'Bill Gates'].


import re
regex = ur"\[P\] (.+?) \[/P\]+?"
line = "President [P] Barack Obama [/P] met Microsoft founder [P] Bill Gates [/P], yesterday."
person = re.findall(regex, line)
print(person)

yields

['Barack Obama', 'Bill Gates']

The regex ur"[\u005B1P\u005D.+?\u005B\u002FP\u005D]+?" is exactly the same unicode as u'[[1P].+?[/P]]+?' except harder to read.

The first bracketed group [[1P] tells re that any of the characters in the list ['[', '1', 'P'] should match, and similarly with the second bracketed group [/P]].That's not what you want at all. So,

  • Remove the outer enclosing square brackets. (Also remove the stray 1 in front of P.)
  • To protect the literal brackets in [P], escape the brackets with a backslash: \[P\].
  • To return only the words inside the tags, place grouping parentheses around .+?.


Try this :

   for match in re.finditer(r"\[P[^\]]*\](.*?)\[/P\]", subject):
        # match start: match.start()
        # match end (exclusive): match.end()
        # matched text: match.group()


Your question is not 100% clear, but I'm assuming you want to find every piece of text inside [P][/P] tags:

>>> import re
>>> line = "President [P] Barack Obama [/P] met Microsoft founder [P] Bill Gates [/P], yesterday."
>>> re.findall('\[P\]\s?(.+?)\s?\[\/P\]', line)
['Barack Obama', 'Bill Gates']


you can replace your pattern with

regex = ur"\[P\]([\w\s]+)\[\/P\]"


Use this pattern,

pattern = '\[P\].+?\[\/P\]'

Check here

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