Python Create List of Objects

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You can create a list of objects using the list comprehension statement [MyObject() for _ in range(n)] that repeats n times the creation of a new object using the MyObject() constructor. The result is a list of n new objects (not copies).

Here’s a minimal example:

class MyObject(object):

def return_objects(n):
    return [MyObject() for _ in range(n)]


You can see that all of them point to different objects in the memory in the following interactive memory visualization. Feel free to go back to step 1 and click through the execution step of the previous code snippet using the Next button:

Create List of Objects using Square Bracket Notation and append()

Everything in Python is an object, even functions and class definitions themselves. A list can hold any object whatsoever. So, technically, every list is a list of objects.

A more explicit way to create a list of objects is creating an initial list by adding comma-separated objects in the square bracket notation [1, 2, 3] and adding more objects one-by-one using list.append().

The following shows a wild assignment of different types of objects into the list using the square bracket notation:

>>> class MyClass: pass
>>> lst = [MyClass(), 'hello', 1, 3.14, MyClass, int, str, list, list()]
>>> lst
[<__main__.MyClass object at 0x0000019E353134F0>, 'hello', 1, 3.14, <class '__main__.MyClass'>, <class 'int'>, <class 'str'>, <class 'list'>, []]

Let’s add three elements using list.append():

>>> lst.append(1)
>>> lst.append(2)
>>> lst.append(3)
>>> lst
[<__main__.MyClass object at 0x0000019E353134F0>, 'hello', 1, 3.14, <class '__main__.MyClass'>, <class 'int'>, <class 'str'>, <class 'list'>, [], 1, 2, 3]

Going to the Next Level

An interesting tutorial for you may be the following on the Finxter blog (human recommendation engine):

🌍 Recommended Tutorial: How to Create a Python List?

Check it out, there’s lots of value there!

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