Python Type and __bases__

Type literal meaning is a kind that can be understood as a stencil, generating various instances through the mold. The built-in function type () in Python allows you to see the concrete type of the instance.

What kind of type is it? Take a look at the following example.

>>> type (BOOL)
<type ' type ' >

>>> Type (str)<type'type'>>>> Type (int)<type'type'>>>> Type (list)<type'type'>>>> Type (dict)<type'type'>>>> Type (set)<type'type'>>>> Type (type)<type'type'>

As you can see, bool,str,int,list,dict,set are type types, and these are basic types.

Take a look at these types of instances:

>>>type (True)<type'BOOL'>>>>type (False)<type'BOOL'>>>> Type ('1234')<type'Str'>>>> type ([1,2,3,4])<type'List'>>>> type ({1,2,3,4})<type'Set'>>>> type ({1:'a', 2:'b', 3:'C', 4:'D'})<type'Dict'>

There is also a type called Class, which is also a template, and its instance is called object.

class Myobjecta (object): ...      Pass  >>> type (myobjecta)'type'>

Class has an inheritance relationship, what kind of subclass is it? All classes in Python inherit object, and what type is Object?

class Myobjectsuba (myobjecta):      ... Pass  >>> type (myobjectsuba)'type'>>>> type ( Object)'type'>

It appears that as long as it is class, the types are type. And look at the types of objects they instantiate.

>>> my_object_a = myobjecta ()>>> type (my_object_a)<class' myobjecta '>>>> my_object_sub_a = Myobjectsuba ()>>> type (my_object_sub_a) <class'myobjectsuba'>

If an object is an instance of who it is, then it is the type of person.

Take a look at __bases__, __bases__ is also a built-in function to see the inheritance of class. Let's look at the following kinds of inherited relationships.

class MYOBJECTB (object): ...      Pass  class  myobjectc (myobjecta, MYOBJECTB)     : ... Pass  >>> MYOBJECTC. __bases__ (<class'myobjecta';, <class'  myobjectb'>)

MYOBJECTC inherit Myobjecta, MYOBJECTB. You can see that the __bases__ of MYOBJECTC is a tuple that contains myobjecta and MYOBJECTB.

You can try the Python tutor

Myobjecta's __bases__ is an object, verified under:

Myobjecta. __bases__ ('object';,)

What is the __base__ of the object?

>>> object. __bases__ ()

An empty tuple.

What is the __bases__ of type?

>>> type. __bases__ ('object';,)

Object

Finally, we can sort out a picture like this.

Python Type and __bases__