I assigned values to a list of strings with a dictionary. How can I sum these values?

Question

cards = ['2','3','4','5','6','7','8','9','10','J','Q','K']

d = {'2':2,'3':3,'4':4,'5':5,'6':6,'7':7,'8':8,'9':9,'10':10,'J':10,'Q':10,'K':10}

How do I sum(cards)? Is it even possible -- I read that the dictionary only maps objects to other objects.

Answer 1

if cards variable contains the labels of the cards you want to add then you can write the following code:

sum_of_cards = sum([d[i] for i in cards] )

Answer 2

Just because it exists:

sum(map(lambda x: d[x], cards))

Or even nicer with what @Chris_Rands suggested:

sum(map(d.get, cards))

Or even this solution using __getitem__ :

sum(map(d.__getitem__, cards))