from urllib.parse import parse_qs, urlparse
def your_decode(qs):
# implement your decryption here
return qs
url = 'http://blah/?id=1&y=[1,2]&blah=dd' # >> replace with request.url
qs = urlparse(url).query
decoded_qs = your_decode(qs)
o = parse_qs(decoded_qs)
print(o)
отпечатки
{'blah': ['dd'], 'id': ['1'], 'y': ['[1,2]']}