how to dynamically create an instance of a class in python?

Question

I have list of class names and want to create their instances dynamically. for example:

names=[
'foo.baa.a',
'foo.daa.c',
'foo.AA',
 ....
]

def save(cName, argument):
 aa = create_instance(cName) # how to do it?
 aa.save(argument)

save(random_from(names), arg)

How to dynamically create that instances in Python? thanks!

Answer 1

Assuming you have already imported the relevant classes using something like

from [app].models import *

all you will need to do is

klass = globals()["class_name"]
instance = klass()

Answer 2

This is often referred to as reflection or sometimes introspection. Check out a similar questions that have an answer for what you are trying to do:

Does Python Have An Equivalent to Java Class forname

Can You Use a String to Instantiate a Class in Python

Answer 3

This worked for me:

from importlib import import_module

class_str: str = 'A.B.YourClass'
try:
    module_path, class_name = class_str.rsplit('.', 1)
    module = import_module(module_path)
    return getattr(module, class_name)
except (ImportError, AttributeError) as e:
    raise ImportError(class_str)