Question

我有一个表格类：

class data:
     person.models.foreignKey("people.person")
     place.models.foreignKey("places.place")

我正在尝试创建一个包含与他们拥有多少连接相关联的人的地方的dict。 IE：

dict={[place1:place2]:count}

因此dict可能如下所示：

dict={[place1:place2]:3, [place1:place3]:2, ect}

到目前为止，我有：

dict={}
datas=data.objects.all()

for data1 in datas:
    for data2 in datas:
        # if dict is empty
        if not dict and data1.person == data2.person and data1.place != data2.place:
            dict[(data1.place, data2.place)]=1
        elif data1.person == data2.person and data1.place != data2.place:
            for assoc, count in dict.items():
                if assoc == (data1.place, data2.place) or assoc == (data2.place, data1.place):
                    count +=1
                else:
                    dict[(data1.place, data2.place)]=1
        else:
            dict[(data1.place, data2.place)]=1

这目前正在返回完全错误的关系，并且永远不会增加计数。我做错了什么？

Answer 1

不要为变量使用dict之类的预定义名称。认为您的问题是您在增加dict [key]时尝试增加计数变量 - 例如dict [key] + = 1

dct = {}
datas = data.objects.all()

for data1 in datas:
    for data2 in datas:
        # if dict is empty
        if not dct and data1.person == data2.person and data1.place != data2.place:
            dct[(data1.place, data2.place)] = 1
        elif data1.person == data2.person and data1.place != data2.place:
            if (data1.place, data2.place) in dct:
                 dct[(data1.place, data2.place)] += 1
            elif (data2.place, data1.place) in dct:
                 dct[(data2.place, data1.place)] += 1
            else:
                 dct[(data1.place, data2.place)] = 1
        else:
            dct[(data1.place, data2.place)] = 1

Answer 2

使用注释。我没有你的模型布局，所以这是逻辑的近似。你需要调整它以根据你的实现映射到正确的东西：

from django.db.models import Count
places = Place.objects.filter(people=thisguy).annotate(connections=Count('people'))

然后，您可以通过每个地方的属性获取连接数：

places[0].connections

从模型django中对匹配字段进行排序和计数

2 个答案: