正则表达式：re.findall（）用于所有字母单词的集合

Question

I'm trying to using re.findall() function to test on a sentence that has a set of all alphabetic words. Here's my code:

import re
s = 'Hello from the other side'
lst = re.findall('[:alpha:]', s)
print (lst)

Any suggestions on how I can change the code?

Answer 1

Python doesn't support the POSIX :alpha: . Write this instead:

re.findall(r'[A-Za-z]+', s)

Avoid use of \\w+ which accepts underscores and numbers in addition to alpha characters. The only real advantage of \\w+ is that it works with the re.LOCALE flag.

When I parse natural sentences to extract entire words, I usually expand the allowed characters to also allow hyphens and apostrophes:

re.findall(r"[A-Za-z\-\']+", s)

This will accept words like "don't" and "re-invent" and "cul-de-sac" but will reject numbers, underscores, whitespace, quote marks, and other punctuation.