给定类类型，如何在Python中创建实例？

Question

Let's say I have this :

class whatever(object):
   def __init__(self):
      pass

and this function:

def create_object(type_name):
   # create an object of type_name

I'd like to be able to call the create_object like this:

inst = create_object(whatever)

and get back an instance of whatever . I think this should be doable without using eval , I'd like to know how to do this. Please notice that I'm NOT using a string as a parameter for create_object .

Answer 1

The most obvious way:

def create_object(type_name):
    return type_name()

Answer 2

def create_object(typeobject):
  return typeobject()

As you so explicitly say that the arg to create_object is NOT meant to be a string, I assume it's meant to be the type object itself, just like in the create_object(whatever) example you give, in which whatever is indeed the type itself.

Answer 3

If I understand correctly, what you want is:

def create_object(type_name, *args):
    # create an object of type_name
    return type_name(*args)

inst = create_object(whatever)

I don't really know why you want to do this, but would be interesting to hear from you what are your reasons to need such a construct.

Answer 4

def create_object(type_name):
   return type_name()

you can of course skip the function altogether and create the instance of whatever like this:

inst = whatever()