Can urllib.parse.quote_plus support lowercase? - python-3.x

Question

Here is an url, like https://www.example.com?timestamp={timestamp}&sign={sign}
And I have caculated the sigh by some algorithm, and got the flowing value.
org_sign = "HBwZu47FkVdQGTyd7uLjfVAQA8nBSwqvE/x3Xv/KFNE=".
Now I want to encode the value and add it to the url.
In urllib.parse.quote_plus, the '/' => '%2F', and '='=>'%3D', so I got 'HBwZu47FkVdQGTyd7uLjfVAQA8nBSwqvE%2Fx3Xv%2FKFNE%3D' .
But I want %2f and %3d, and then HBwZu47FkVdQGTyd7uLjfVAQA8nBSwqvE%2fx3Xv%2fKFNE%3d. And I cannot change the whole sign to a lower case directly, like sign.lower(). Because it is a sign, it is case-sensitive.
Python 3.7.2
>>> from urllib import parse
>>> org_sign = "HBwZu47FkVdQGTyd7uLjfVAQA8nBSwqvE/x3Xv/KFNE="
>>> parse.quote_plus(org_sign)
'HBwZu47FkVdQGTyd7uLjfVAQA8nBSwqvE%2Fx3Xv%2FKFNE%3D'
And I read the document in urllib. It doesn't mention any thing about case-sensitive.

Answer 1

This workaround works for me:
import urllib.parse
class LowerCaseQuoter(urllib.parse.Quoter):
def __missing__(self, b):
# Handle a cache miss. Store quoted string in cache and return.
res = chr(b) if b in self.safe else '%{:02x}'.format(b)
self[b] = res
return res
urllib.parse._safe_quoters[b''] = LowerCaseQuoter(b'').__getitem__
Original string: /media/Filmy/PohadkyCD/Sofie Prvni/Season 1 (2013-2014) + pilot/1x00.Sofie První, Byla jednou jedna princezna (Once Upon a Princess).avi
Encoded string by urllib.parse.quote(filename, safe=''): %2fmedia%2fFilmy%2fPohadkyCD%2fSofie%20Prvni%2fSeason%201%20%282013-2014%29%20%2b%20pilot%2f1x00.Sofie%20Prvn%c3%ad%2c%20Byla%20jednou%20jedna%20princezna%20%28Once%20Upon%20a%20Princess%29.avi