如何使用正则表达式或替换来清理列表？

Question

This seems like a very obvious mistake which I have been trying to solve for almost an hour now. :(

lst = ['\xa0\xa0+11-9188882266\xa0\xa0+01-9736475634 ','\xa0\xa0+11-9177772266\xa0\xa0+01-9736475234']

I am trying to grab numbers, hyphens and the + sign only. Basically remove all the \\xa0 .

I thought that Regex would be the right way to go about it. Tried it and failed:

mRegex = (['+0-9-'])
lst = re.match(mRegex,lst)

Traceback (most recent call last): File "", line 1, in File "C:\\Python34\\lib\\re.py", line 160, in match return _compile(pattern, flags).match(string) File "C:\\Python34\\lib\\re.py", line 282, in _compile p, loc = _cache[type(pattern), pattern, flags] TypeError: unhashable type: 'list'

I gave it a few more tries with regex then switched to replace :

h.replace(r"\\xa0","")

It doesn't do anything to the lst . Stays exactly the same.

When I do a len(lst[0]) I get 33 which is very odd.

In a:

for i in lst[0]:
    print(i)

the output doesn't show \\xa0 .

I am completely confused here.

Answer 1

first, you cannot apply replacement/regex on a list. You have to apply them for each string, and use a list comprehension to rebuild the cleaned-up list.

second, when you replace you're using the raw prefix, when you shouldn't use it, since it treats \\x literally, not that you want.

I'd do:

lst = [x.replace("\xa0","") for x in lst]

results in:

['+11-9188882266+01-9736475634 ', '+11-9177772266+01-9736475234']

and BTW: mRegex = (['+0-9-']) doesn't work because you're basically defining a list of 1 string. You probably meant mRegex = '([0-9\\-+])'

A regex solution would be:

lst = [re.sub(r"[^\d+\-]","",x) for x in lst]

(removes chars not matching the char class, and \\d is (roughly) equivalent to 0-9 )

After a few years I realize (after reading OP comment properly this time) that the expected result is probably the numbers separated in a list, so removing \\xa0 isn't a good idea, because it collates the numbers. Let's just use split on each string:

>>> lst = ['\xa0\xa0+11-9188882266\xa0\xa0+01-9736475634 ','\xa0\xa0+11-9177772266\xa0\xa0+01-9736475234']
>>> [x.split() for x in lst]
[['+11-9188882266', '+01-9736475634'], ['+11-9177772266', '+01-9736475234']]

Actually using split() works because \\xa0 is seen as a space character (windows uses it for instance), and also removes multiple instances of spaces, so the result is given straight away without further hassle.