non-django querystring handling

querystring_to_dict.py

'''
Reminder for handling querystrings outside of django.

Notes...
- It's legal to have duplicate keys
- This is a messy, real openURL, with three foo test keys
- foo1 shows that a string with a comma is still parsed as a single string
- foo2 shows that a key without a val is ignored
- foo3 shows that a key with an `=` but without a val is also ignored
'''

import pprint
from urllib import parse


url = '''https://bruknow.library.brown.edu/discovery/openurl?institution=01BU_INST&vid=01BU_INST:BROWN&date=2020&rft_val_fmt=info:ofi%2Ffmt:kev:mtx:book&aulast=Reed&rft_id=info:oclcnum%2F1122724548&rft_id=urn:ISBN:9781566895842&isbn=9781566895842&rfr_id=info:sid%2Ffirstsearch.oclc.org:WorldCat&linktype=openurl&rft.isbn=9781566895842&pid=1122724548%3Cfssessid%3E0%3C%2Ffssessid%3E&rft.genre=unknown&rft.genre=unknown&rft.aufirst=Justin&title=The%20malevolent%20volume&title=Brown%20University&aufirst=Justin&sid=FirstSearch:WorldCat&rft.aulast=Reed&req_dat=%3Csessionid%3E0%3C%2Fsessionid%3E&url_ver=Z39.88-2004&rft.date=2020&checksum=23ee504fe7c47fc1a54186fc2e68bd86&rfe_dat=%3Caccessionnumber%3E1122724548%3C%2Faccessionnumber%3E&id=doi:&detail=RBN&rft.title=The%20malevolent%20volume&foo1=barA,barB&foo2&foo3='''
print( f'\nurl, ``{url}``' )

parse_obj = parse.urlsplit( url )
querystring = parse_obj.query
print( f'\nquerystring, ``{querystring}``' )

initial_dict = parse.parse_qs( querystring )
assert type( initial_dict ) == dict
print( f'\ninitial_dict, ``{pprint.pformat(initial_dict)}``' )

final_dct = {}
for ( key, val ) in initial_dict.items():
    if len(val) == 1:
        final_dct[key] = val[0]
    else:
        final_dct[key] = val
print( f'\nfinal_dict, ``{pprint.pformat(final_dct)}``' )


# ----------
# output...
# ----------

# url, ``https://bruknow.library.brown.edu/discovery/openurl?institution=01BU_INST&vid=01BU_INST:BROWN&date=2020&rft_val_fmt=info:ofi%2Ffmt:kev:mtx:book&aulast=Reed&rft_id=info:oclcnum%2F1122724548&rft_id=urn:ISBN:9781566895842&isbn=9781566895842&rfr_id=info:sid%2Ffirstsearch.oclc.org:WorldCat&linktype=openurl&rft.isbn=9781566895842&pid=1122724548%3Cfssessid%3E0%3C%2Ffssessid%3E&rft.genre=unknown&rft.genre=unknown&rft.aufirst=Justin&title=The%20malevolent%20volume&title=Brown%20University&aufirst=Justin&sid=FirstSearch:WorldCat&rft.aulast=Reed&req_dat=%3Csessionid%3E0%3C%2Fsessionid%3E&url_ver=Z39.88-2004&rft.date=2020&checksum=23ee504fe7c47fc1a54186fc2e68bd86&rfe_dat=%3Caccessionnumber%3E1122724548%3C%2Faccessionnumber%3E&id=doi:&detail=RBN&rft.title=The%20malevolent%20volume&foo1=barA,barB&foo2&foo3=``

# querystring, ``institution=01BU_INST&vid=01BU_INST:BROWN&date=2020&rft_val_fmt=info:ofi%2Ffmt:kev:mtx:book&aulast=Reed&rft_id=info:oclcnum%2F1122724548&rft_id=urn:ISBN:9781566895842&isbn=9781566895842&rfr_id=info:sid%2Ffirstsearch.oclc.org:WorldCat&linktype=openurl&rft.isbn=9781566895842&pid=1122724548%3Cfssessid%3E0%3C%2Ffssessid%3E&rft.genre=unknown&rft.genre=unknown&rft.aufirst=Justin&title=The%20malevolent%20volume&title=Brown%20University&aufirst=Justin&sid=FirstSearch:WorldCat&rft.aulast=Reed&req_dat=%3Csessionid%3E0%3C%2Fsessionid%3E&url_ver=Z39.88-2004&rft.date=2020&checksum=23ee504fe7c47fc1a54186fc2e68bd86&rfe_dat=%3Caccessionnumber%3E1122724548%3C%2Faccessionnumber%3E&id=doi:&detail=RBN&rft.title=The%20malevolent%20volume&foo1=barA,barB&foo2&foo3=``

# initial_dict, ``{'aufirst': ['Justin'],
#  'aulast': ['Reed'],
#  'checksum': ['23ee504fe7c47fc1a54186fc2e68bd86'],
#  'date': ['2020'],
#  'detail': ['RBN'],
#  'foo1': ['barA,barB'],
#  'id': ['doi:'],
#  'institution': ['01BU_INST'],
#  'isbn': ['9781566895842'],
#  'linktype': ['openurl'],
#  'pid': ['1122724548<fssessid>0</fssessid>'],
#  'req_dat': ['<sessionid>0</sessionid>'],
#  'rfe_dat': ['<accessionnumber>1122724548</accessionnumber>'],
#  'rfr_id': ['info:sid/firstsearch.oclc.org:WorldCat'],
#  'rft.aufirst': ['Justin'],
#  'rft.aulast': ['Reed'],
#  'rft.date': ['2020'],
#  'rft.genre': ['unknown', 'unknown'],
#  'rft.isbn': ['9781566895842'],
#  'rft.title': ['The malevolent volume'],
#  'rft_id': ['info:oclcnum/1122724548', 'urn:ISBN:9781566895842'],
#  'rft_val_fmt': ['info:ofi/fmt:kev:mtx:book'],
#  'sid': ['FirstSearch:WorldCat'],
#  'title': ['The malevolent volume', 'Brown University'],
#  'url_ver': ['Z39.88-2004'],
#  'vid': ['01BU_INST:BROWN']}``

# final_dict, ``{'aufirst': 'Justin',
#  'aulast': 'Reed',
#  'checksum': '23ee504fe7c47fc1a54186fc2e68bd86',
#  'date': '2020',
#  'detail': 'RBN',
#  'foo1': 'barA,barB',
#  'id': 'doi:',
#  'institution': '01BU_INST',
#  'isbn': '9781566895842',
#  'linktype': 'openurl',
#  'pid': '1122724548<fssessid>0</fssessid>',
#  'req_dat': '<sessionid>0</sessionid>',
#  'rfe_dat': '<accessionnumber>1122724548</accessionnumber>',
#  'rfr_id': 'info:sid/firstsearch.oclc.org:WorldCat',
#  'rft.aufirst': 'Justin',
#  'rft.aulast': 'Reed',
#  'rft.date': '2020',
#  'rft.genre': ['unknown', 'unknown'],
#  'rft.isbn': '9781566895842',
#  'rft.title': 'The malevolent volume',
#  'rft_id': ['info:oclcnum/1122724548', 'urn:ISBN:9781566895842'],
#  'rft_val_fmt': 'info:ofi/fmt:kev:mtx:book',
#  'sid': 'FirstSearch:WorldCat',
#  'title': ['The malevolent volume', 'Brown University'],
#  'url_ver': 'Z39.88-2004',
#  'vid': '01BU_INST:BROWN'}``