How to remove symbols from a string with Python? [duplicate]

Solution 1:

One way, using regular expressions:

>>> s = "how much for the maple syrup? $20.99? That's ridiculous!!!"
>>> re.sub(r'[^\w]', ' ', s)
'how much for the maple syrup   20 99  That s ridiculous   '

• \w will match alphanumeric characters and underscores

• [^\w] will match anything that's not alphanumeric or underscore

Solution 2:

Sometimes it takes longer to figure out the regex than to just write it out in python:

import string
s = "how much for the maple syrup? $20.99? That's ricidulous!!!"
for char in string.punctuation:
    s = s.replace(char, ' ')

If you need other characters you can change it to use a white-list or extend your black-list.

Sample white-list:

whitelist = string.letters + string.digits + ' '
new_s = ''
for char in s:
    if char in whitelist:
        new_s += char
    else:
        new_s += ' '

Sample white-list using a generator-expression:

whitelist = string.letters + string.digits + ' '
new_s = ''.join(c for c in s if c in whitelist)

Solution 3:

I often just open the console and look for the solution in the objects methods. Quite often it's already there:

>>> a = "hello ' s"
>>> dir(a)
[ (....) 'partition', 'replace' (....)]
>>> a.replace("'", " ")
'hello   s'

Short answer: Use string.replace().