Python How to loop only selected keys and their value in a dictionary

Question

How to iterate only selected key in a python dictionary?

    for k, v in myDict:
        print ('key = {}'.format(k))
        print ("value = {}".format(v))

This will print out all keys and its values. Lets say I only want key1, key2 and key5, and their values, any idea?

Thank you

Then you should use if statement in the loop to check for that, there is no such thing as "looping over some part of the collection" unless you use filter. — Ali Beyit, Mar 11 '20 at 10:24
@Ali Well… `for k, v in (i for i in myDict.items() if i[0] in ('key1', ...)):` — deceze, Mar 11 '20 at 10:25
@deceze so O(n^2) is better than O(log(n)) you say? :) Even though your answer looks like a one liner very clean looking code, in reality it is just slower than checking the condition with if in a loop. — Ali Beyit, Mar 11 '20 at 11:10

score 1 · Accepted Answer · answered Mar 11 '20 at 10:26

With a simple if statement.

Note : don't forget .items() to iterate over keys + values in a dictionary

myDict = {
    "key1": 3,
    "key2": 2,
    "key3": 5,
    "key4": 8,
    "key5": 1,
    "key6": 4
}
desired_keys = ["key1", "key2", "key5"]
for k, v in myDict.items():
    if k in desired_keys:
        print ('key = {}'.format(k))
        print ("value = {}".format(v))

Output :

key = key1
value = 3
key = key2
value = 2
key = key5
value = 1

Python How to loop only selected keys and their value in a dictionary

1 Answers1