[Python] How can I dynamically create derived classes from a base class

For example I have a base class as follows:

class BaseClass(object):
def __init__(self, classtype):
self._type = classtype


From this class I derive several other classes, e.g.

class TestClass(BaseClass):
def __init__(self):
super(TestClass, self).__init__('Test')

class SpecialClass(BaseClass):
def __init__(self):
super(TestClass, self).__init__('Special')


Is there a nice, pythonic way to create those classes dynamically by a function call that puts the new class into my current scope, like:

foo(BaseClass, "My")
a = MyClass()
...


As there will be comments and questions why I need this: The derived classes all have the exact same internal structure with the difference, that the constructor takes a number of previously undefined arguments. So, for example, MyClass takes the keywords a while the constructor of class TestClass takes b and c.

inst1 = MyClass(a=4)
inst2 = MyClass(a=5)
inst3 = TestClass(b=False, c = "test")


But they should NEVER use the type of the class as input argument like

inst1 = BaseClass(classtype = "My", a=4)


I got this to work but would prefer the other way, i.e. dynamically created class objects.

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