使用python中的re.sub函数删除字符串中的特殊字符和撇号以及多余的空格

Question

import re
def removePunctuation(text):

    return re.sub(r'[ \W,_,]+', ' ', text.lower()).lstrip()
print removePunctuation('Hi, 'you!')
print removePunctuation(' No's under_score!')

i want result :

hi you
nos under score 

Answer 1

You may try this,

def removePunctuation(text):
    return re.sub(r'^\s+|\s+$|[^A-Za-z\d\s]', '', text.lower())

or

Seems like you want to replace all the underscore with space and all the other special chars with an empty string.

>>> re.sub(r'^\s+|\s+$|[^A-Za-z\d\s]', '', " No's under_score!".lower().replace('_', ' '))
'nos under score'
>>> re.sub(r'^\s+|\s+$|[^A-Za-z\d\s]', '', " Hi, 'you!'".lower().replace('_', ' '))
'hi you'

Answer 2

Regex is a wonderful string manipulation tool, but within python it at times may be an overkill, and this particular example is one of its kind. Python has some thought over neatly crafted string libraries that can do wonders without regex and for this example str.translate and unicode.translate is ideal

For Python 2.X

def removePunctuation(text):
    from string import punctuation
    return ' '.join(text.translate(None, punctuation))

For Unicode and Python 3.X

def removePunctuationU(text):
    from string import punctuation
    return u' '.join(text.translate({ord(c): None for c in punctuation}).split())