How to write a specific dict comprehension?

Question

I got this question at an interview and I did not know how to solve it then and I am trying to solve it now.

If I have two lists:

l1 = [1, 3, 5, 7, 9]
l2 = [0, 2, 4, 8, 10]

how can I write a dict comprehension that will produce {1:0, 3:2, 5:4, 7:8, 9:10}?

`{first: second for first, second in zip(l1, l2)}` – Abdul Niyas P M Jan 16 '22 at 12:50 — Abdul Niyas P M, Jan 16 '22 at 12:50
Or you can make it even short by `dict(zip(l1, l2))` – Abdul Niyas P M Jan 16 '22 at 12:53 — Abdul Niyas P M, Jan 16 '22 at 12:53

score 2 · Answer 1 · answered Jan 16 '22 at 12:55

2

l1 = [1, 3, 5, 7, 9]
l2 = [0, 2, 4, 8, 10]
dict(zip(l1, l2))

output:

{1: 0, 3: 2, 5: 4, 7: 8, 9: 10}

answered Jan 16 '22 at 12:55

Tal Folkman

score 0 · Answer 2 · edited Jan 16 '22 at 13:02

0

You can use the zip built-in function to combine multiple lists into an iterable of tuples. This zip iterable can be made into a dictionary.

for (valueoflist1,valueoflist2) in zip(list1,list2):
   #Code

result = {key: val for key ,val in zip(keys ,values)}

or

    result = dict(zip(keys, values))

edited Jan 16 '22 at 13:02

Simon Crowe

answered Jan 16 '22 at 12:55

XxJames07-

You should avoid using `dict` as a variable name. – Tom Aarsen Jan 16 '22 at 12:58
i know, i'll fix that bad habit someday – XxJames07- Jan 16 '22 at 12:58
Note: There is no need for the parentheses around the names to be unpacked, and it's slightly better style to omit them (and include spaces after the `:` and `,`), e.g. `{vl1: vl2 for vl1, vl2 in zip(lst1, lst2)}` – ShadowRanger Jan 16 '22 at 13:03

2 Answers2