How to make nested for a loop more Pythonic

Question

I need to create a list of blocked users by key. Each user has several attributes, and if any of these attributes is in the keys, the user is blocked.

I wrote the following nested for-loop, and it works for me, but I want to write it in a more pythonic way with fewer lines and a more readable way. How can i do this?

for key in keys:
    key.blocked_users = []

for user in get_users():
    for attribute in user.attributes:
        for key in keys:
            if attribute.name == key.name:
                key.blocked_users.append(user)

Answer 1

, , Python. , , - , ?:)

, . , "". , ( ) ( ) :

for key in keys:
    key.blocked_users = []

keyname_map = {key.name: key.blocked_users for key in keys}  # map the key name to blocked_user list
keynames = set(keyname_map)

set(keyname_map) - , , .

set.intersection, , :

for user in get_users():
    for key in keynames.intersection({attribute.name for attribute in user.attributes}):
        keyname_map[key].append(user)

set.intersection .

, attribute.name key.name .

Answer 2

for -loop:

for key in keys:
    keyname = key.name
    key.blocked_users = [user for user in get_users() if any(attribute.name == keyname for attribute in user)]

Answer 3

, for , , . , .

, , , .

for "" , itertools.product. :

>>> from itertools import product
>>> a = [1, 2]
>>> b = [3, 4]
>>> c = [5]
>>> for x in product(a, b, c): x
... 
(1, 3, 5)
(1, 4, 5)
(2, 3, 5)
(2, 4, 5)

Answer 4

, Pythonic, - :

[key.blocked_users.append(user) for key in keys 
        for attribute in user.attributes 
        for user in get_users() 
        if attribute.name == key.name]