Most efficient way to search in list of dicts

Question

I have the following list of dicts.

people = [
{'name': "Tom", 'age': 10},
{'name': "Mark", 'age': 5},
{'name': "Pam", 'age': 7}
]

Which would be the most optimized way in terms of performance to search in list of dicts. Following are different some methods:

next((item for item in dicts if item["name"] == "Pam"), None)

OR

filter(lambda person: person['name'] == 'Pam', people)

OR

def search(name):
    for p in people:
        if p['name'] == name:
            return p

OR

def search_dictionaries(key, value, list_of_dictionaries):
    return [element for element in list_of_dictionaries if element[key] == value]

Any other method is also welcome. Thanks.

Answer 1

Doing a quick timeit on the functions show that using filter seems to be the fastest of all the methods

%timeit filter(lambda person: person['name'] == 'Pam', people)

1000000 loops, best of 3: 263 ns per loop

• Using next produces a time of 731ns
• Using the search method produces a time of 361ns
• And lastly the seach_dictionaries uses 811ns

Answer 2

If you are searching for a single item then this is the "best" approach

def search(name):
    for p in people:
        if p['name'] == name:
            return p

All the other implementations will iterate over all the items in the list, whereas this one will stop once the item is found