在 Python 字典中按其值删除键答案

【问题标题】：Delete Key by its value in Python Dictionary在 Python 字典中按其值删除键
【发布时间】：2021-09-20 13:16:37
【问题描述】：

我有一个字典，我想在其中删除名称以 S 开头的键，即“person_3”。


    My_Dict = {
        "person_1": {"name": 'John', "age": 22, "Interests": ['football","cricket'],
                     "amount_deposited": [24000, 26000]},

        "person_2": {"name": 'Nancy James', "age": 23, "Interests": ['baseball’,’cricket'],
                     "amount_deposited": [24000, 27000]},

        "person_3": {"name": 'Selena Gomez', 'age': 26, "Interests": ['baseball', 'table tennis'],
                     "amount_deposited": [24000, 28000]}
            }

【问题讨论】：

标签： python dictionary functional-programming

【解决方案1】：

在遍历旧字典时使用字典理解并测试名称。

my_new_dict = {person: subdict for person, subdict in My_Dict.items() if My_Dict[person]['name'][0].lower() != 's'}

获得这个 my_new_dict：

{'person_1': {'name': 'John', 'age': 22, 'Interests': ['football","cricket'], 'amount_deposited': [24000, 26000]}, 'person_2': {'name': 'Nancy James', 'age': 23, 'Interests': ['baseball’,’cricket'], 'amount_deposited': [24000, 27000]}}

【讨论】：

也许有助于解释听写理解

【解决方案2】：

试试del

My_Dict = {
        "person_1": {"name": 'John', "age": 22, "Interests": ['football","cricket'],
                     "amount_deposited": [24000, 26000]},

        "person_2": {"name": 'Nancy James', "age": 23, "Interests": ['baseball’,’cricket'],
                     "amount_deposited": [24000, 27000]},

        "person_3": {"name": 'Selena Gomez', 'age': 26, "Interests": ['baseball', 'table tennis'],
                     "amount_deposited": [24000, 28000]}
            }

keys_to_be_deleted = []

# first we need to get the keys which we need to delete
for each_person in My_Dict:
    if(My_Dict[each_person]['name'].lower().startswith('s')):
        keys_to_be_deleted.append(each_person)

# now that we have the keys, we can delete them       
for k in keys_to_be_deleted:
    del My_Dict[k]
    
My_Dict

# {'person_1': {'name': 'John',
#   'age': 22,
#   'Interests': ['football","cricket'],
#   'amount_deposited': [24000, 26000]},
#  'person_2': {'name': 'Nancy James',
#   'age': 23,
#   'Interests': ['baseball’,’cricket'],
#   'amount_deposited': [24000, 27000]}}

【讨论】：