Difference between inheriting from object and object.class for python?

Question

I can see code below

class MetaStrategy(StrategyBase.__class__): pass

I am not sure why not just write code like below

class MetaStrategy(StrategyBase): pass

Definition schematic

class StrategyBase(DataAccessor):
    pass

class DataAccessor(LineIterator):
    pass

class LineIterator(with_metaclass(MetaLineIterator, LineSeries)):
    pass

def with_metaclass(meta, *bases):
    class metaclass(meta):
        def __new__(cls, name, this_bases, d):
            return meta(name, bases, d)
    return type.__new__(metaclass, str('temporary_class'), (), {})

those would do two completely different things. The first inherits from the class of StrategyBase, which itself is presumably a class, and __call__ is either type or another metaclass. MetaStrategy would inherit from StrategyBse — juanpa.arrivillaga
– juanpa.arrivillaga, Commented Aug 1, 2022 at 8:13
StrategyBase.__class__ is StrategyBase's metaclass, which is entirely different from the class StrategyBase itself. — blhsing
– blhsing, Commented Aug 1, 2022 at 8:19
First the user-defined classes extends Object class by default. Also Object class implements a set of methods and variables which are common to all the objects being created in the application. This is the main reason why we have Object class as a base class for all the other classes. So in your case, the inheritance will be either direct or indirect. — LSeu
– LSeu, Commented Aug 1, 2022 at 8:19

bwe69 · Accepted Answer · 2022-08-01 08:40:33Z

1

If you call self.__class__ from a subclass instance, self.__class__ will use that type of the subclass.

Any class that is expressly specified while using the class will be used naturally.

Take the example below:

class Foo(object):
    def create_new(self):
        return self.__class__()

    def create_new2(self):
        return Foo()

class Bar(Foo):
    pass

b = Bar()
c = b.create_new()
print type(c)  # We got an instance of Bar
d = b.create_new2()
print type(d)  # we got an instance of Foo

answered Aug 1, 2022 at 8:40

bwe69

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