如果日期不在查询集中添加默认值

Question

我正在将 django 与 chartjs 集成。我使用如下所示的基于类的视图。

class SingleTagChartJSONView(BaseLineOptionsChartView):

    def get_context_data(self, **kwargs):
        context = super(BaseLineChartView, self).get_context_data(**kwargs)

        date_year = int(str(context["year"]))
        date_month = int(str(context["month"]))

        specific_date = datetime(date_year, date_month, 1)
        obj_tags = mitop_tags.objects.filter(
                tag_publish_date__year=specific_date.year,
                tag_publish_date__month=specific_date.month,
                post_tag_single=str(context['tag'])).extra(
                      {'day' : "date(tag_publish_date)"}
                    ).values('day').annotate(
                        tag_occur=Count('post_tag_single'))

我得到这样的 obj_tags 输出：

{'day': datetime.date(2020, 10, 16), 'tag_occur': 3}
{'day': datetime.date(2020, 10, 17), 'tag_occur': 3}
{'day': datetime.date(2020, 10, 18), 'tag_occur': 1}
{'day': datetime.date(2020, 10, 19), 'tag_occur': 2}
{'day': datetime.date(2020, 10, 20), 'tag_occur': 1}
{'day': datetime.date(2020, 10, 22), 'tag_occur': 6}
{'day': datetime.date(2020, 10, 23), 'tag_occur': 8}
{'day': datetime.date(2020, 10, 24), 'tag_occur': 8}
{'day': datetime.date(2020, 10, 26), 'tag_occur': 8}
{'day': datetime.date(2020, 10, 27), 'tag_occur': 6}
{'day': datetime.date(2020, 10, 28), 'tag_occur': 6}
{'day': datetime.date(2020, 10, 30), 'tag_occur': 3}
{'day': datetime.date(2020, 10, 31), 'tag_occur': 7}

我想为查询集中不存在的日期（记录）添加默认值。

{'day': datetime.date(2020, 10, 1), 'tag_occur': 0}

在这种情况下，从 1-15 然后缺少 25 和 29。 期望的输出

{'day': datetime.date(2020, 10, 1), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 2), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 3), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 4), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 5), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 6), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 7), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 8), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 9), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 10), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 11), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 12), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 13), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 14), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 15), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 16), 'tag_occur': 3}
{'day': datetime.date(2020, 10, 17), 'tag_occur': 3}
{'day': datetime.date(2020, 10, 18), 'tag_occur': 1}
{'day': datetime.date(2020, 10, 19), 'tag_occur': 2}
{'day': datetime.date(2020, 10, 20), 'tag_occur': 1}
{'day': datetime.date(2020, 10, 22), 'tag_occur': 6}
{'day': datetime.date(2020, 10, 23), 'tag_occur': 8}
{'day': datetime.date(2020, 10, 24), 'tag_occur': 8}
{'day': datetime.date(2020, 10, 25), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 26), 'tag_occur': 8}
{'day': datetime.date(2020, 10, 27), 'tag_occur': 6}
{'day': datetime.date(2020, 10, 28), 'tag_occur': 6}
{'day': datetime.date(2020, 10, 29), 'tag_occur': 0}
{'day': datetime.date(2020, 10, 30), 'tag_occur': 3}
{'day': datetime.date(2020, 10, 31), 'tag_occur': 7}

该输出应按日期排序。 最后输出到 chartjs 数据集

在此处预览实际问题： https://consuming-olm-0670.dataplicity.io/mi_top/statistic/tag/f1/10/2020

Answer 1

假设您的查询集如下所示：

obj_tags = [
    {'day': datetime.date(2020, 10, 1), 'tag_occur': 4},
    ...
    {'day': datetime.date(2020, 10, 22), 'tag_occur': 31},
]

你可以创建一个空的dict列表，并在里面添加queryset的数据：

import datetime

d1 = datetime.date(2020, 10, 1)
d2 = datetime.date(2020, 10, 31)
all_empty_tags = [{'day':d1 + datetime.timedelta(days=x), 'tag_occur': 0} for x in range((d2-d1).days + 1)]

for key, value in enumerate(all_empty_tags):
    try:
        new_tag_occur = [item['tag_occur'] for item in obj_tags if item["day"] == value["day"]][0]
        dd[key]['tag_occur'] = new_tag_occur
    except IndexError:
        pass

您将拥有所有数据