列表推导 - 从字典中的字典中提取值

Question

我正在尝试从字典词典中获取名单列表......

list = {'1':{'name':'fred'}, '2':{'name':'john'}}

# this code works a-ok
for key, value in list.items():
    names = []
    for key, value in list.items():
        names.append(value['name'])



# and these consecutive comprehensions also work...
keys = [value for key, value in list.items()]


names = [each['name'] for each in keys]

但最后两个如何组合？

Answer 1

>>> d = {'1':{'name':'fred'}, '2':{'name':'john'}}

您可以对列表理解使用以下修改

>>> [value.get('name') for key, value in d.items()]
['john', 'fred']

虽然在这种情况下，你不需要key来做任何事情，所以你可以做到

>>> [value.get('name') for value in d.values()]
['john', 'fred']

Answer 2

names = [value['name'] for value in list.values()]

Answer 3

names = [value['name'] for key, value in list.items()]

由于value部分是在for部分中定义的，因此您可以对value执行对理解项目部分的操作。如上所述，您可以使用list.values()来简化此操作。

Answer 4

names = [value['name'] for key, value in list.items()]