假设我有这个:
[
{"name": "Tom", "age": 10},
{"name": "Mark", "age": 5},
{"name": "Pam", "age": 7}
]
通过搜索“Pam”作为名称,我想检索相关的字典:{name:“Pam”,年龄:7}
如何做到这一点?
假设我有这个:
[
{"name": "Tom", "age": 10},
{"name": "Mark", "age": 5},
{"name": "Pam", "age": 7}
]
通过搜索“Pam”作为名称,我想检索相关的字典:{name:“Pam”,年龄:7}
如何做到这一点?
当前回答
将接受的答案放在函数中,以便于重用
def get_item(collection, key, target):
return next((item for item in collection if item[key] == target), None)
也可以写成
get_item_lambda = lambda collection, key, target : next((item for item in collection if item[key] == target), None)
结果
key = "name"
target = "Pam"
print(get_item(target_list, key, target))
print(get_item_lambda(target_list, key, target))
#{'name': 'Pam', 'age': 7}
#{'name': 'Pam', 'age': 7}
如果键可能不在目标字典中,请使用dict。get和避免KeyError
def get_item(collection, key, target):
return next((item for item in collection if item.get(key, None) == target), None)
get_item_lambda = lambda collection, key, target : next((item for item in collection if item.get(key, None) == target), None)
其他回答
我的第一个想法是,你可能想要考虑为这些字典创建一个字典……举个例子,如果你要多次搜索它。
然而,这可能是一个不成熟的优化。有什么问题:
def get_records(key, store=dict()):
'''Return a list of all records containing name==key from our store
'''
assert key is not None
return [d for d in store if d['name']==key]
将接受的答案放在函数中,以便于重用
def get_item(collection, key, target):
return next((item for item in collection if item[key] == target), None)
也可以写成
get_item_lambda = lambda collection, key, target : next((item for item in collection if item[key] == target), None)
结果
key = "name"
target = "Pam"
print(get_item(target_list, key, target))
print(get_item_lambda(target_list, key, target))
#{'name': 'Pam', 'age': 7}
#{'name': 'Pam', 'age': 7}
如果键可能不在目标字典中,请使用dict。get和避免KeyError
def get_item(collection, key, target):
return next((item for item in collection if item.get(key, None) == target), None)
get_item_lambda = lambda collection, key, target : next((item for item in collection if item.get(key, None) == target), None)
你可以使用列表推导式:
def search(name, people):
return [element for element in people if element['name'] == name]
在我看来,这是最python的方式:
people = [
{'name': "Tom", 'age': 10},
{'name': "Mark", 'age': 5},
{'name': "Pam", 'age': 7}
]
filter(lambda person: person['name'] == 'Pam', people)
result(在Python 2中作为列表返回):
[{'age': 7, 'name': 'Pam'}]
注意:在python3中,返回一个filter对象。所以python3的解决方案是:
list(filter(lambda person: person['name'] == 'Pam', people))
@Frédéric Hamidi的回答很好。在Python 3中。X .next()的语法稍有改变。因此有一个小小的修改:
>>> dicts = [
{ "name": "Tom", "age": 10 },
{ "name": "Mark", "age": 5 },
{ "name": "Pam", "age": 7 },
{ "name": "Dick", "age": 12 }
]
>>> next(item for item in dicts if item["name"] == "Pam")
{'age': 7, 'name': 'Pam'}
正如@Matt在评论中提到的,你可以添加一个默认值:
>>> next((item for item in dicts if item["name"] == "Pam"), False)
{'name': 'Pam', 'age': 7}
>>> next((item for item in dicts if item["name"] == "Sam"), False)
False
>>>