CBV源码分析

# ModelViewSet继承View(django原生View)
# APIView继承了View

# 先读View

# urls.py
    path('books1/', views.Books.as_view()),  # 在这个地方应该写一个函数内存地址,views.Books.as_view()执行完，是一个函数内存地址，as_view是一个类方法，类直接来调用，会把类自动传入
放了一个view的内存地址(View--->as_view--->内层函数)

# 请求来了，如果路径匹配，会执行，函数内存地址(request)
def view(request, *args, **kwargs):
    # request是当次请求的request
    self = cls(**initkwargs)  # 实例化得到一个对象，Book对象
    if hasattr(self, 'get') and not hasattr(self, 'head'):
        self.head = self.get
        self.setup(request, *args, **kwargs)
        if not hasattr(self, 'request'):
            raise AttributeError(
                "%s instance has no 'request' attribute. Did you override "
                "setup() and forget to call super()?" % cls.__name__
            )
            return self.dispatch(request, *args, **kwargs)
        
def dispatch(self, request, *args, **kwargs):
        # request是当次请求的request  self是book对象
        if request.method.lower() in self.http_method_names:
            # handler现在是
            # handler = getattr(self,'get')  你写的Book类的get方法的内存地址
            handler = getattr(self, request.method.lower(), self.http_method_not_allowed)
        else:
            handler = self.http_method_not_allowed
        return handler(request, *args, **kwargs)  # 执行get(request)