unescape example @ 2.17 在字符串中处理html和xml not working on Python3.9

[xiaobojiang]

Original example

s = 'Spicy "Jalapeño&quot.'
from html.parser import HTMLParser
p = HTMLParser()
p.unescape(s)
'Spicy "Jalapeño".'

after Python 3.9, 'HTMLParser' object has no attribute 'unescape', this method is removed.

a working example of Python 3.9 :
s = 'Spicy "Jalapeño&quot.'
import html
p = html
p.unescape(s)

ref link: coursera-dl/coursera-dl#778

[zlu27]

@xiaobojiang
Should we add some "translator comments"?

[xiaobojiang]

good idea.
we could do it in the footer area, or add a note in below.