Python - 替换字符串中的非ascii字符（»）

Question

I need to replace in a string the character "»" with a whitespace, but I still get an error. This is the code I use:

# -*- coding: utf-8 -*-
from bs4 import BeautifulSoup

# other code

soup = BeautifulSoup(data, 'lxml')
mystring = soup.find('a').text.replace(' »','')

UnicodeEncodeError: 'ascii' codec can't encode character u'\\xbb' in position 13: ordinal not in range(128)

But If I test it with this other script:

# -*- coding: utf-8 -*-
a = "hi »"
b = a.replace('»','') 

It works. Why this?

Answer 1

In order to replace the content of string using str.replace() method; you need to firstly decode the string, then replace the text and encode it back to the original text:

>>> a = "hi »"
>>> a.decode('utf-8').replace("»".decode('utf-8'), "").encode('utf-8')
'hi '

You may also use the following regex to remove all the non-ascii characters from the string:

>>> import re
>>> re.sub(r'[^\x00-\x7f]',r'', 'hi »')
'hi '

Answer 2

@Moinuddin Quadri's answer fits your use-case better, but in general, an easy way to remove non-ASCII characters from a given string is by doing the following:

# the characters '¡' and '¢' are non-ASCII
string = "hello, my name is ¢arl... ¡Hola!"

all_ascii = ''.join(char for char in string if ord(char) < 128)

This results in:

>>> print(all_ascii)
"hello, my name is arl... Hola!"

You could also do this:

''.join(filter(lambda c: ord(c) < 128, string))

But that's about 30% slower than the char for char ... approach.