Question

嗨，我正在尝试编写一些代码，该代码比较多个嵌套词典与特定项目的匹配情况，如果为true，则返回外键。

我尝试使用嵌套的for循环和字典名称列表来排序和查找匹配项，代码首先获取单个字典dict1和dict2，然后比较每个字典中的['ID']键进行匹配，请参见下文：

Dictionary1 = {'key1':{'ID':'ID1'}, 'key2':{'ID':'ID2'}, 'key3':{'ID':'ID3'}}

Dictionary2 = {'key4':{'ID':'ID1'}, 'key5':{'ID':'ID2'}, 'key6':{'ID':'ID3'}}



DictionaryList = [Dictionary1, Dictionary2]


for Dict1 in DictionaryList:
    for Dict2 in DictionaryList:
        for Key1 in Dict1:
            for Key2 in Dict2:
                if Dict1[Key1]['ID'] == Dict2[Key2]['ID']:
                    print('Dictionary1' + ': ' + Key1 + ' // ' 'Dictionary2' + ': ' + Key2)

此代码返回12个匹配项及其外键，其中大多数是错误的，请参见下文：

Dictionary1: key1 // Dictionary2: key1
Dictionary1: key2 // Dictionary2: key2
Dictionary1: key3 // Dictionary2: key3
Dictionary1: key1 // Dictionary2: key4
Dictionary1: key2 // Dictionary2: key5
Dictionary1: key3 // Dictionary2: key6
Dictionary1: key4 // Dictionary2: key1
Dictionary1: key5 // Dictionary2: key2
Dictionary1: key6 // Dictionary2: key3
Dictionary1: key4 // Dictionary2: key4
Dictionary1: key5 // Dictionary2: key5
Dictionary1: key6 // Dictionary2: key6

我怀疑这是因为字典彼此匹配数次，即代码将Dictionary1与Dictionary1比较，然后将Dictionary2与Dictionary2比较，依此类推。

预期结果将是打印3个匹配项的代码：

Dictionary1: key1 // Dictionary2: key4
Dictionary1: key2 // Dictionary2: key5
Dictionary1: key3 // Dictionary2: key6

我是python / programming的新手，所以将不胜感激。

Answer 1

我不确定您为什么将字典合并到一个列表中，然后尝试对其进行迭代。您本可以简单地使用字典本身：

for Key1 in Dictionary1:
    for Key2 in Dictionary2:
        if Dictionary1[Key1]['ID'] == Dictionary2[Key2]['ID']:
            print('Dictionary1' + ': ' + Key1 + ' // ' 'Dictionary2' + ': ' + Key2)

这将打印

Dictionary1: key1 // Dictionary2: key4
Dictionary1: key2 // Dictionary2: key5
Dictionary1: key3 // Dictionary2: key6

Answer 2

您可以创建一个反向映射字典，将Dictionary2中的ID映射到其键，以便通过迭代Dictionary1并将每个ID映射到对应的ID，从而在线性时间内获得所需的输出。通过反向映射字典键入Dictionary2：

mapping = {d['ID']: k for k, d in Dictionary2.items()}
for k, d in Dictionary1.items():
    print('Dictionary1' + ': ' + k + ' // ' 'Dictionary2' + ': ' + mapping[d['ID']])

这将输出：

Dictionary1: key1 // Dictionary2: key4
Dictionary1: key2 // Dictionary2: key5
Dictionary1: key3 // Dictionary2: key6

匹配嵌套字典中的项目并返回外键

2 个答案: