如何将新的键值对添加到字典列表中的现有键值对中？

Question

I have a dictionary with a parent-key and its value is a dict. I want to extract a key,val pair from a list of dict.

given:

{"Premier" : {}}

I want to extract:

 all_compseasons = content: [
    {
        label: "2019/20",
        id: 274
    },
    {
        label: "2018/19",
        id: 210
    }]

So to get:

{"Premier" : 
    {"2019/20" : 274, 
    "2018/19" : 210
    }
}

I can't seem to find a good way to do it. I've tried below given other examples of the problem, but doesn't work.

compseasons = {}
for comp in all_compseasons:
    competition_id = 'Premier'
    index = competition_id
    compseasons[index]comp['label'] = comp['id']

Answer 1

Your very close. Dictionary keys need to be referenced with surrounding [] , so comp['label'] should be [comp['label']] . You can also just use the given dictionary {"Premier" : {}} instead of creating a new one with compseasons = {} , but either will give you the same result.

Working solution:

d = {"Premier": {}}

all_compseasons = [{"label": "2019/20", "id": 274}, {"label": "2018/19", "id": 210}]

for comp in all_compseasons:
    d["Premier"][comp["label"]] = comp["id"]

print(d)
# {'Premier': {'2019/20': 274, '2018/19': 210}}

Answer 2

You just made a mistake in how you declared compseasons and how you are accessing the value of premier key which is also a dictionary.

Declaring compseasons = {"Premier" : {}} will not give you KeyError when you are trying to access it via compseasons[index] since Premier has already been inserted as a key.

Second, since your value of Premier itself is a dictionary, you should access the inner key enclosed in [] which would translate to compseasons[index][comp['label']] = comp['id'] .

all_compseasons = [
{
    'label': "2019/20",
    'id': 274
},
{
    'label': "2018/19",
    'id': 210
}]

compseasons = {"Premier" : {}}

for comp in all_compseasons:
    competition_id = 'Premier'
    index = competition_id
    compseasons[index][comp['label']] = comp['id']