Find object by its member inside a List in python

Question

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?

Answer 1

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 ;-)