如何用适当的unicode字符替换转义的unicode字符？

Question

I have a string as such:

'https://www.jobtestprep.co.uk/media/24543/xnumber-series-big-1.png,qanchor\\u003dcenter,amode\\u003dcrop,awidth\\u003d473,aheight\\u003d352,arnd\\u003d131255524960000000.pagespeed.ic.YolXsWmhs0.png'

I need to replace an arbitrary escaped unicode character ( '\\\\uXXXX' ) with its equivalent unescaped unicode character ( '\\uXXXX' ). I've got Regex to extract all of the necessary parts (the '\\\\uXXXX' part and the 'XXXX' part for re.sub() ) but I can't find a way to replace the right part with \\u{}\u003c/code> as Python gives a Unicode error and wants a pre-filled in character such as '\=' . Using raw strings doesn't work as '\\u{}\u0026#39; is just converted back into '\\\\u{}\u0026#39; and we end up back where we started.

Is there a way to do this? If you want an example of the code you can have a look at it here:

# data loaded from a https://www.google.com/search image search

results_source = urllib.request.urlopen(url_request).read().decode()
searched_results = re.findall(r"(?<=,\"ou\":\")[^\s]+[\w](?=\",\"ow\")", results_source)

for count, unicode in enumerate(re.findall(r"(?<=\\u)....", searched_results[i])):
    searched_results[i] = re.sub(re.findall(r"\\u....", searched_results[i])[count], r"\u{}".format(unicode), searched_results[i])

searched_results is a list of results returned. An example of an item in the list would be the string given above.

Answer 1

Your regex extracts JSON strings from a webpage:

searched_results = re.findall(r"(?<=,\"ou\":\")[^\s]+[\w](?=\",\"ow\")", results_source)

Those " chacarters you removed were actually significant. The \\uxxxx escape syntax here is specific to JSON (and Javascript) syntax; they are closely related to Python's use but different (not much, but it matters when you have non-BMP codepoints).

You can trivially decode them as JSON , if you keep the quotes in there:

searched_results = map(json.loads, re.findall(r"(?<=,\"ou\":)\"[^\s]+[\w]\"(?=,\"ow\")", results_source))

Better still would be to use a HTML library to parse the page. When using BeautifulSoup , you can get the data with:

import json
from bs4 import BeautifulSoup

soup = BeautifulSoup(results_source, 'html.parser')
search_results = [json.loads(t.text)['ou'] for t in soup.select('.rg_meta')]

This loads the text contents of each <div class="rg_meta" ...> element as JSON data, and extracts the ou key from each of the resulting dictionaries. No regular expressions required.

Answer 2

You can do in this way.

>>> url = (
...    'https://www.jobtestprep.co.uk/media/24543/xnumber-series-'
...    'big-1.png,qanchor\\u003dcenter,amode\\u003dcrop,awidth\\u003d473,'
...    'aheight\\u003d352,arnd\\u003d131255524960000000.pagespeed.ic.YolXsWmhs0.png'
... )
>>> url = url.encode('utf-8').decode('unicode_escape')
>>> print(url)
https://www.jobtestprep.co.uk/media/24543/xnumber-series-big-1.png,qanchor=center,amode
=crop,awidth=473,aheight=352,arnd=131255524960000000.pagespeed.ic.YolXsWmhs0.png
>>>