我通常不会以最好的方式编写我的Python代码,因为我相对较新,有人要求我对Django应用程序进行更改,因为代码看起来不太好
这就是它的样子:
@login_required
def submission_set_rank(request):
r1_obj_id = request.GET.get('rank1','')
r2_obj_id = request.GET.get('rank2','')
r3_obj_id = request.GET.get('rank3','')
r4_obj_id = request.GET.get('rank4','')
r5_obj_id = request.GET.get('rank5','')
#rate the first BallotStats object
ballot_1 = BallotStats.objects.get(object_id=r1_obj_id)
ballot_2 = BallotStats.objects.get(object_id=r2_obj_id)
ballot_3 = BallotStats.objects.get(object_id=r3_obj_id)
ballot_4 = BallotStats.objects.get(object_id=r4_obj_id)
ballot_5 = BallotStats.objects.get(object_id=r5_obj_id)
ballot_1.score += 5
ballot_2.score += 4
ballot_3.score += 3
ballot_4.score += 2
ballot_5.score += 1
ballot_1.save()
ballot_2.save()
ballot_3.save()
ballot_4.save()
ballot_5.save()
return HttpResponseRedirect('/submissions/results/film/')
事实证明,我意识到我一直在用这种方式编写我的Python代码,有没有办法让它看起来更好而不是占用21行代码?
答案 0 :(得分:6)
在你的情况下,一点点的循环根本不会受到伤害。事实上,作为一般规则,每当你必须重复两次以上的事情时,试着让它成为一个循环。
n = 5
for i in range(1, n+1):
obj_id = request.GET('rank' + str(i), '')
ballot = BallotStats.objects.get(object_id=obj_id)
ballot.score += n - i + 1
ballot.save()
答案 1 :(得分:6)
最大的问题不是代码的样式 - 而是你要进行10次查询:5个用于获取对象,5个用于更新它们。
立即使用__in
过滤掉对象:
@login_required
def submission_set_rank(request):
keys = {'rank1': 5, 'rank2': 4, 'rank3': 3, 'rank4': 2, 'rank5': 1}
ranks = [request.GET.get(key,'') for key in keys]
for ballot in BallotStats.objects.filter(object_id__in=ranks):
ballot.score += keys[ballot.object_id]
ballot.save()
return HttpResponseRedirect('/submissions/results/film/')
这最多可以进行6次查询:1次获取对象,5次更新。
此外,你可以"标记"使用commit_manually
装饰器的视图(commit_on_success
也适合您)。它应speed up things significantly:
@login_required
@transaction.commit_manually
def submission_set_rank(request):
keys = {'rank1': 5, 'rank2': 4, 'rank3': 3, 'rank4': 2, 'rank5': 1}
ranks = [request.GET.get(key,'') for key in keys]
for ballot in BallotStats.objects.filter(object_id__in=ranks):
ballot.score += keys[ballot.object_id]
ballot.save()
transaction.commit()
return HttpResponseRedirect('/submissions/results/film/')
我强烈感觉你甚至可以在一次更新查询中执行此操作。例如,在executemany()
的帮助下直接使用connection.cursor()
:
@login_required
def submission_set_rank(request):
keys = {'rank1': 5, 'rank2': 4, 'rank3': 3, 'rank4': 2, 'rank5': 1}
ranks = [{'score': request.GET.get(key,''), 'id': key} for key in keys]
cursor = connection.cursor()
cursor.executemany("""
UPDATE
ballot_stats
SET
score = score + %(score)s
WHERE
object_id = %(id)s
""", ranks)
return HttpResponseRedirect('/submissions/results/film/')
确保字段和表名称正确无误。
答案 2 :(得分:1)