用正则表达式去除标点符号 - python

Question

I need to use regex to strip punctuation at the start and end of a word. It seems like regex would be the best option for this. I don't want punctuation removed from words like 'you're', which is why I'm not using .replace().

Answer 1

You don't need regular expression to do this task. Use str.strip with string.punctuation :

>>> import string
>>> string.punctuation
'!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~'
>>> '!Hello.'.strip(string.punctuation)
'Hello'

>>> ' '.join(word.strip(string.punctuation) for word in "Hello, world. I'm a boy, you're a girl.".split())
"Hello world I'm a boy you're a girl"

Answer 2

I think this function will be helpful and concise in removing punctuation:

import re
def remove_punct(text):
    new_words = []
    for word in text:
        w = re.sub(r'[^\w\s]','',word) #remove everything except words and space
        w = re.sub(r'_','',w) #how to remove underscore as well
        new_words.append(w)
    return new_words

Answer 3

If you persist in using Regex, I recommend this solution:

import re
import string
p = re.compile("[" + re.escape(string.punctuation) + "]")
print(p.sub("", "\"hello world!\", he's told me."))
### hello world hes told me

Note also that you can pass your own punctuation marks:

my_punct = ['!', '"', '#', '$', '%', '&', "'", '(', ')', '*', '+', ',', '.',
           '/', ':', ';', '<', '=', '>', '?', '@', '[', '\\', ']', '^', '_', 
           '`', '{', '|', '}', '~', '»', '«', '“', '”']

punct_pattern = re.compile("[" + re.escape("".join(my_punct)) + "]")
re.sub(punct_pattern, "", "I've been vaccinated against *covid-19*!") # the "-" symbol should remain
### Ive been vaccinated against covid-19

Answer 4

You can remove punctuation from a text file or a particular string file using regular expression as follows -

new_data=[]
with open('/home/rahul/align.txt','r') as f:
    f1 = f.read()
    f2 = f1.split()



    all_words = f2 
    punctuations = '''!()-[]{};:'"\,<>./?@#$%^&*_~''' 
    # You can add and remove punctuations as per your choice 
    #removing stop words in hungarian text and  english text and 
    #display the unpunctuated string
    # To remove from a string, replace new_data with new_str 
    # new_str = "My name$#@ is . rahul -~"

    for word in all_words: 
        if word not in punctuations:
           new_data.append(word)

    print (new_data)

PS - Do the identation properly as per required. Hope this helps!!