Inheritance relationships for classes in Python rest-framework (As_view)

I. BACKGROUND

In recent days have been learning the source code of the RESTful framework, the process of user request, in the routing system this block encountered a question, about the class inheritance relationship, when the request came in to route this block, execute the As_view () method, why run the parent view of the As_view ( ) method to perform the dispatch method to Apiview? I'll record it over here, and I'll check it back.

Two. Code examples

1. Routing

 from Import URL  from Import  = [    url (r'^index/', Api_view. Indexview.as_view ()),]

2. View class

 from Import   Responsefromimport  apiviewclass  Indexview (apiview):     def  Get (self,request):        return Response ('... ')

Three. Source Code Analysis

A. As_view method of Apiview

classApiview (View): @classmethoddefAs_view (CLS, * *Initkwargs):ifIsinstance (GetAttr (CLS,'Queryset', None), Models.query.QuerySet):defforce_evaluation ():RaiseRuntimeError ('Do not evaluate the '. Queryset ' attribute directly,'                    'As the result would be cached and reused between requests.'                    'Use '. All () ' or call '. Get_queryset () ' instead.') Cls.queryset._fetch_all=force_evaluation View= Super (Apiview, CLS). As_view (* *Initkwargs)#here is the method that inherits the parent class As_view ()View.cls=CLS View.initkwargs=InitkwargsreturnCsrf_exempt (view)

# Too much code only intercepts part of the code

B. What do super (APIVIEW,CLS) As_view (**initkwargs) do

# Super (Apiview,self) first finds Apiview's parent class (that is, class View) and then converts the As_view property of the View class to the properties of the class Apiview # equivalent to copying code from view As_view () to As_view in Api_view

So finally run super (APIVIEW,CLS). As_view (**initkwargs) executes the As_view method in view

classView (object): Http_method_names= ['Get','Post','put','Patch','Delete','Head','Options','Trace']    def __init__(Self, * *Kwargs): forKey, ValueinchSix.iteritems (Kwargs): SetAttr (self, key, value) @classonlymethoddefAs_view (CLS, * *Initkwargs): forKeyinchInitkwargs:ifKeyinchCls.http_method_names:RaiseTypeError ("You tried to pass in the %s method name as a"                                "keyword argument to%s (). Don ' t do that."% (key, CLS.__name__))            if  nothasattr (CLS, key):RaiseTypeError ("%s () received an invalid keyword%r. As_view"                                "Only accepts arguments that is already"                                "attributes of the class."% (CLS.__name__, key)) defView (Request, *args, * *Kwargs): self= CLS (* *Initkwargs)ifHasattr (Self,'Get') and  notHasattr (Self,'Head'): Self.head=Self.get self.request=Request Self.args=args Self.kwargs=KwargsreturnSelf.dispatch (Request, *args, * *Kwargs)#run here, and finally execute the Self.dispatch.View.view_class =CLS View.view_initkwargs=Initkwargs update_wrapper (view, CLS, updated=()) Update_wrapper (view, Cls.dispatch, assigned=())        returnView#returns the View function

Inheritance relationships for classes in Python rest-framework (As_view)