Find object by its member inside a List in python

find, list, python, search

Solution

You might want to pre-index them -

from collections import defaultdict

class Mock(object):
    age_index = defaultdict(list)

    def __init__(self, name, age):
        self.name = name
        self.age = age
        Mock.age_index[age].append(self)

    @classmethod
    def find_by_age(cls, age):
        return Mock.age_index[age]

Edit: a picture is worth a thousand words:

X axis is number of Mocks in myList, Y axis is runtime in seconds.

- red dots are @dcrooney's filter() method

- blue dots are @marshall.ward's list comprehension

- green dots hiding behind the X axis are my index ;-)

Problem

lets assume the following simple Object: ``` class Mock: def __init__(self, name, age): self.name = name self.age = age ``` then I have a list with some Objects like this: ``` myList = [Mock("Dan", 34), Mock("Jack", 30), Mock("Oli", 23)...] ``` Is there some built-in feature where I can get all Mocks with an age of ie 30? Of course I can iterate myself over them and compare their ages, but something like ``` find(myList, age=30) ``` would be nice. Is there something like that?

Original source

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