從 python 字典中刪除值

Question

早上好。 我有一些嵌套字典，每個鍵有多個項目。 我只需要提取包含只有“ans”和“val”對的項目的對，如果項目包含“ans”、“type”、“value”等，那么我想刪除它。 我擁有的字典示例和預期的 output 如下所示。 歡迎任何建議，非常感謝

數據

dict_i_have = {
    "x19": [
        {
            "ans": "Enter number",
            "type": "number",
            "value": "input_val",
            "validators": [
                {"dype": "int", "invalid": "Enter number between 0 and 100", "min": 0, "max": 100},
                {"vtype": "no", "message": "Please enter a value"},
            ],
        },
        {"ans": "One year or less", "val": "-10"},
        {"ans": "Do not know", "val": "1"},
        {"ans": "Other", "val": "3"},
    ],
    "x20": [
        {
            "ans": "Enter number",
            "type": "number",
            "value": "input_val",
            "validators": [
                {"dype": "int", "invalid": "Enter number between 0 and 50", "min": 0, "max": 50},
                {"vtype": "no", "message": "Please enter a value"},
            ],
        },
        {"ans": "Six months or less", "val": "10"},
    ],
}

預計 output

dict_i_want = {'x19': [{'ans': 'One year or less', 'val': '-10'},
                       {'ans': 'Do not know', 'val': '1'},
                       {'ans': 'Other', 'val': '3'}],
               'x20': [{'ans': 'Six months or less', 'val': '10'}]}

Answer 1

從字面上看，將您的 dicts 列表過濾為恰好具有兩個鍵的那些，並且具有您感興趣的兩個鍵值。

dict_i_want = dict()
for key, values in dict_i_have.items():
     subdicts = [d for d in values if len(d) == 2 and 'ans' in d and 'val' in d]
     dict_i_want[key] = subdicts

Answer 2

嘗試以下簡單的解決方案，

    dict_i_have = {
        "x19": [
            {
                "ans": "Enter number",
                "type": "number",
                "value": "input_val",
                "validators": [
                    {"dype": "int", "invalid": "Enter number between 0 and 100", "min": 0, "max": 100},
                    {"vtype": "no", "message": "Please enter a value"},
                ],
            },
            {"ans": "One year or less", "val": "-10"},
            {"ans": "Do not know", "val": "1"},
            {"ans": "Other", "val": "3"},
        ],
        "x20": [
            {
                "ans": "Enter number",
                "type": "number",
                "value": "input_val",
                "validators": [
                    {"dype": "int", "invalid": "Enter number between 0 and 50", "min": 0, "max": 50},
                    {"vtype": "no", "message": "Please enter a value"},
                ],
            },
            {"ans": "Six months or less", "val": "10"},
        ],
    }
    
# Actual Solution starts here
    for key1 in dict_i_have:
        for val in dict_i_have[key1]:
            if len(val) > 2 :
                dict_i_have[key1].remove(val)
                
    print(dict_i_have)

Answer 3

您可以通過字典理解來做到這一點：

dict_i_have = {
    # elided for brevity
}

dict_i_want = {
    key: [
        {"ans": q["ans"], "val": q["val"]} for q in questions if "val" in q
    ]
    for (key, questions) in dict_i_have.items()
}
print(dict_i_want)

或者，如果您想保留對原始字典的引用而不是將它們復制到新字典中，

dict_i_want = {
    key: [q for q in questions if set(q) == {"ans", "val"}]
    for (key, questions) in dict_i_have.items()
}
print(dict_i_want)

Answer 4

使用字典keys function 可以得到字典中的鍵。
然后將其與{"ans", "val"}進行比較以過濾掉不需要的字典。

for key in dict_i_have.keys():
    dict_i_have[key] = [item for item in dict_i_have[key] if set(item.keys()) == {'ans', 'val'}]