正则表达式以匹配仅包含3个或更少大写单词的引号中的字符串

Question

I've searched and searched, but can't find an any relief for my regex woes.

I wrote the following dummy sentence:

Watch Joe Smith Jr. and Saul "Canelo" Alvarez fight Oscar de la Hoya and Genaddy Triple-G Golovkin for the WBO belt GGG. Canelo Alvarez and Floyd 'Money' Mayweather fight in Atlantic City, New Jersey. Conor MacGregor will be there along with Adonis Superman Stevenson and Mr. Sugar Ray Robinson. "Here Goes a String". 'Money Mayweather'. "this is not a-string", "this is not A string", "This IS a" "Three Word String".

I'm looking for a regular expression that will return the following when used in Python 3.6:

Canelo, Money, Money Mayweather, Three Word String

The regex that has gotten me the closest is:

(["'])[A-Z](\\?.)*?\1

I want it to only match strings of 3 capitalized words or less immediately surrounded by single or double quotes. Unfortunately, so far it seem to match any string in quotes, no matter what the length, no matter what the content, as long is it begins with a capital letter.

I've put a lot of time into trying to hack through it myself, but I've hit a wall. Can anyone with stronger regex kung-fu give me an idea of where I'm going wrong here?

Answer 1

Try to use this one: (["'])((?:[AZ][az]+ ?){1,3})\\1

(["']) - opening quote

([AZ][az]+ ?){1,3} - Capitalized word repeating 1 to 3 times separated by space

[AZ] - capital char (word begining char)

[az]+ - non-capital chars (end of word)

_? - space separator of capitalized words ( _ is a space), ? for single word w/o ending space

{1,3} - 1 to 3 times

\\1 - closing quote, same as opening

Group 2 is what you want.

Match 1
Full match  29-37   `"Canelo"`
Group 1.    29-30   `"`
Group 2.    30-36   `Canelo`
Match 2
Full match  146-153 `'Money'`
Group 1.    146-147 `'`
Group 2.    147-152 `Money`
Match 3
Full match  318-336 `'Money Mayweather'`
Group 1.    318-319 `'`
Group 2.    319-335 `Money Mayweather`
Match 4
Full match  398-417 `"Three Word String"`
Group 1.    398-399 `"`
Group 2.    399-416 `Three Word String`

RegEx101 Demo: https://regex101.com/r/VMuVae/4

Answer 2

Working with the text you've provided, I would try to use regular expression lookaround to get the words surrounded by quotes and then apply some conditions on those matches to determine which ones meet your criterion. The following is what I would do:

[p for p in re.findall('(?<=[\'"])[\w ]{2,}(?=[\'"])', txt) if all(x.istitle() for x in p.split(' ')) and len(p.split(' ')) <= 3]

txt is the text you've provided here. The output is the following:

# ['Canelo', 'Money', 'Money Mayweather', 'Three Word String']

Cleaner:

matches = []

for m in re.findall('(?<=[\'"])[\w ]{2,}(?=[\'"])', txt):
    if all(x.istitle() for x in m.split(' ')) and len(m.split(' ')) <= 3:
        matches.append(m)


print(matches)

# ['Canelo', 'Money', 'Money Mayweather', 'Three Word String']

Answer 3

这是我的工作： ([\\"'])(([AZ][^ ]*? ?){1,3})\\1