从字典列表中提取新字典

Question

I have a list of dictionaries, I would like to create a new dictionary where the first key 'value' corresponds to the second value of the 'b' key of each dictionary in the list. The second key 'number' of the new dictionary corresponds to the third (therefore last) value of the 'b' key of each dictionary in the list.

my_list = [
    {
        'a': (2.6, 0.08, 47.0, 1),
        'b': (5.7, 0.05, 1)
    },
    {
        'a': (2.6, 0.08, 47.0, 2),
        'b': (5.7, 0.06, 2)
    }
]

expected output:

new_dic = {'value': (0.05, 0.06), number = (1, 2)}

Answer 1

you can use comprehension as follows:

new_dict = {}
new_dict['value'] = tuple(val['b'][1] for val in my_list)
new_dict['number'] = tuple(val['b'][2] for val in my_list)

Note that you need to call the tuple constructor, because (val['b'][2] for val in my_list) alone returns a generator object.