Iterating Over a Dictionary using functions

Question

def big_keys(dicta,x):
    for k in dicta:
        if x < dicta.get(k,0):
            return k

for this function, I want it to input dicta which is a dictionary and x is int. and it should return all the k that have value more than x. however it only return one of the k and not all of them. e.g big_keys({"a":20 ,"b":20 ,"c":10},15) → ["a", "b"]
but my out put is ["a"]

If you want to *return a list*, then somewhere you have to *create a list* and *append to it* and at the end *return the list*… — deceze, Apr 09 '21 at 08:35

CallMeStag · Accepted Answer · 2021-04-09T15:56:15.467

A minimum effort solution would be to gather all suitable k in a list and return that list:

def big_keys(dicta,x):
    results = []
    for k in dicta:
        if x < dicta.get(k,0):
            results.append(k)

However you can write that more compactly and efficient with list comprehension:

def big_keys(dicta, x):
    return [k for k in dicta if x < dicta[k]]

note that there is no need for dicta.get(k, 0), as k in dicta is guaranteed by the fact that we're iterating over dicta.

EDIT: iterating over dicta.items() instead of calling dicta[k] is of course also valid; I'm not sure if one is significantly faster than the other …

EDIT: Just ran a simple timeit and dicta.items() is indeed faster

Iterating Over a Dictionary using functions

1 Answers1