python - Speeding up django .exists() -


i have query translationstep.objects.filter(step_id=pk). need check if object exist or not , if so, return object (or several objects). have read .exists() more fastest way it, should make 2 requests.

if translationstep.objects.filter(step_id=pk).exists():  return translationstep.objects.filter(step_id=pk) else:  return none

how can optimise it?

you shouldn't @ all. filter() return empty queryset if there no match, false in boolean context.


Comments

Post a Comment

Popular posts from this blog

angular - Converting AngularJS deffered promise to AngularX observable for JSOM -

i converting angularjs application angular 4 gets data sharepoint. using jsom , executequeryasync() method. i data executequeryasync() server , store in observable in service. code have transform old version (which not me) below. struggle syntax when converting service. have absolute no plan how convert angular 4. getallstatusreps($scope) { const deferred = $q.defer(); const ctx = sp.clientcontext.get_current(); const web = ctx.get_web(); const statuslist = web.get_lists().getbytitle(this.statuslistname); const twitterlist = web.get_lists().getbytitle(this.twitterlistname); const statreps = statuslist.getitems(this.getqueryforallstatusreps()); const twitreps = twitterlist.getitems(this.getqueryforallstatusreps()); const querytext = ` <view> <rowlimit>1</rowlimit> <viewfields>{0}</viewfields> <query> <where><isnotnull><fieldref name=...
Read more

python - What's the Pythonic way to report nonfatal errors in a parser? -

a parser created reads recorded chess games file. api used this: import chess.pgn pgn_file = open("games.pgn") first_game = chess.pgn.read_game(pgn_file) second_game = chess.pgn.read_game(pgn_file) # ... sometimes illegal moves (or other problems) encountered. pythonic way handle them? raising exceptions error encountered. however, makes every problem fatal, in execution stops. often, there still useful data has been parsed , returned. also, can not continue parsing next data set, because still in middle of half-read data. accumulating exceptions , raising them @ end of game. makes error fatal again, @ least can catch , continue parsing next game. introduce optional argument this: game = chess.pgn.read_game(pgn_file, parser_info) if parser_info.error: # appears quite verbose. # can @ least make best of sucessfully parsed parts. # ... are of these or other methods used in wild? actually, are fatal errors -- @ least, far being able repro...
Read more

python - AssertionError when trying to assert return value from two dictionaries with py.test -

i'm testing text-based game i've been making learn python. last few days have been busy finding solution problem keep encountering. have tried multiple test methods, end giving me same error. the problem following assertionerror (using py.test ): e assertionerror: assert <textgame.waffle.winefields object @ 0x03bdecd0> == <textgame.waffle.winefields object @ 0x03bd00d0> obviously, object ( textgame.waffle.winefields ) correct, location different. don't care location. assume because i'm using 2 separate dictionaries same contents. however, prefer keep using dictionary if possible. the minimal working example of test looks follows: import textgame.waffle def test_change_map(): roomnames = { "the wine fields" : textgame.waffle.winefields(), } room = "the wine fields" next_room = roomnames[room] assert textgame.waffle.map(room).change(room) == next_room the textgame.waffle game i'm ...
Read more