python - 如果其他元素使用理解匹配，则从两个字典列表中提取元素

Question

如何迭代两个字典列表，通过键匹配列表之间的字典，如果存在匹配，则将每个字典中的特定键附加到新字典中的键值对中。让我用一个例子来澄清:

l1 = [{'id': 52, 'email': 'someemail@yahoo.com', 'anotherfield': 'some value'},
       .....
      {'id': 98, 'email': 'anotheremail@yahoo.com', 'anotherfield': 'another value'}]

l2 = [{'id': 93, 'email': 'someemail@yahoo.com', 'another key': 'seventeen'},
       .....
      {'id': 101, 'email': 'anotheremail@yahoo.com', 'another key': 'twenty'}]


# match the 'email' keys between each list, and if match, create k, v pair from id's

desired_output = {'52': 93.....'98': 101}

通过简单地迭代每个列表，我可以很容易地实现这一点，如下所示:

lookup = dict()
for l in l1:
    for p in l2:
        if l['email']==p['email']:
            lookup[l['id']]=p['id']
            break

但是这有点笨拙，我更喜欢某种理解。我的尝试:

lookup = {k['id']: v['id'] for k, v in zip(l1, l2) if k['email'] == v['email']}

Answer 1

试试这个:

from itertools import product
lookup = {k['id']: v['id'] for k, v in product(l1, l2) if k['email'] == v['email']}