Dynamic Class Creation

The class keyword is merely syntactic sugar. Python transforms it behind the scenes into a type(name, bases, namespace) call. The following two definitions produce exactly the same class:

class Example:
	attr = 1

	def method(self):
		return "method"

name = "Example"
bases = ()
namespace = {
	"attr": 1,
	"method": lambda self: "method"
}

Example = type(name, bases, namespace)

print(f"{Example.__class__=}")     # <class 'type'>
print(f"{Example().attr=}")        # 1
print(f"{Example().method()=}")    # 'method'

assert isinstance(Example, type)
assert isinstance(Example(), Example)

The Three Arguments

In the type(name, bases, namespace) call:

• name — the name of the class (written to the __name__ attribute).
• bases — a tuple of inherited classes; an empty tuple means deriving from object.
• namespace — a dictionary containing all assignments in the class body: attributes, methods, __module__, __qualname__, etc.

Why Does This Matter?

Dynamic class creation is useful when you need to determine class names or attributes at runtime — for example, when an ORM generates table definitions from code, or when a plugin system registers plugins. This is also the first step to understanding metaclasses: a metaclass is a class that takes the place of type and controls this type(name, bases, namespace) call.