Create a class at run-time

[Steve Holden]

Michel wrote:
> Thanks Peter.
> 
> I searched a little bit more and wrote the following example:
> 
> ------------------------------------
> import types
> 
> class MyClass:
> 
>     def test_toto(self):
>         print type(self)
>         print self.name
> 
> def test_toto(self):
>     print type(self)
>     print self.name
> 
> MyDynClass = types.ClassType("MyDynClass", (object, ), {})
> MyDynClass.__module__ = "test.complex.hierarchy"
> MyDynClass.test_toto = test_toto
> 
> t1 = MyDynClass()
> t2 = MyDynClass()
> 
> t1.name = "Marcel"
> t2.name = "Oscar"
> 
> t1.test_toto()
> t2.test_toto()
> 
> c1 = MyClass()
> c1.name = "Raoul"
> c1.test_toto()
> --------------------------------
> 
> the output is:
> 
> <class 'test.complex.hierarchy.MyDynClass'>
> Marcel
> <class 'test.complex.hierarchy.MyDynClass'>
> Oscar
> <type 'instance'>
> Raoul
> 
> I'm wondering why the type of the self parameter is not 'instance' in
> the calls
> t1.test_toto() and t2.test_toto()
> 
> The rest of the behavior is correct though, so I guess it's just
> internal Python stuff.
> 
Yes, it's just that MyClass is an old-style class (its type is <type
'classobj'>) whereas MyDynClass is a new-style class (its type is <type
'type'>, because it inherits from object).

It's as though you had written

class MyClass:
   ...

class MyDynClass(object):
   ...

regards
 Steve
-- 
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