Question

I figure out how to remove special non alphanumeric character in python using the following function:

p_nonalphanum = re.compile('\W+')

def removeNonAlphaNum(string):
        m = p_nonalphanum.match(string)
        if m:
            string = string[m.end():]
        return string

I would like to keep some specials characters though such as ½, ¾ which i consider as number. How should i edit my regex?

e.g: from “• ½ cup flour” to “½ cup flour”

Answer 1

>>> def remove_unwanted(s):
...     '''• ½ cup flour -> ½ cup flour'''
...     allowed = '[\w½¾]+'
...     return ' '.join(re.findall(allowed, s))
... 
>>> print remove_unwanted('• ½ cup flour ->')
½ cup flour