（1）dispatch
def dispatch(self, request, *args, **kwargs): """ `.dispatch()` is pretty much the same as Django's regular dispatch, but with extra hooks for startup, finalize, and exception handling. """ self.args = args self.kwargs = kwargs #对原始request进行加工，丰富了一些功能 #Request( # request, # parsers=self.get_parsers(), # authenticators=self.get_authenticators(), # negotiator=self.get_content_negotiator(), # parser_context=parser_context # ) #request(原始request,[BasicAuthentications对象，]) #获取原生request,request._request #获取认证类的对象，request.authticators #1.封装request request = self.initialize_request(request, *args, **kwargs) self.request = request self.headers = self.default_response_headers # deprecate? try: #2.认证 self.initial(request, *args, **kwargs) # Get the appropriate handler method if request.method.lower() in self.http_method_names: handler = getattr(self, request.method.lower(), self.http_method_not_allowed) else: handler = self.http_method_not_allowed response = handler(request, *args, **kwargs) except Exception as exc: response = self.handle_exception(exc) self.response = self.finalize_response(request, response, *args, **kwargs) return self.response（2）initial
def initial(self, request, *args, **kwargs): """ Runs anything that needs to occur prior to calling the method handler. """ self.format_kwarg = self.get_format_suffix(**kwargs) # Perform content negotiation and store the accepted info on the request neg = self.perform_content_negotiation(request) request.accepted_renderer, request.accepted_media_type = neg # Determine the API version, if versioning is in use. #request.version获取版本信息 #request.versioning_scheme获取处理版本你的对象 version, scheme = self.determine_version(request, *args, **kwargs) request.version, request.versioning_scheme = version, scheme # Ensure that the incoming request is permitted #4.实现认证 self.perform_authentication(request) #5.权限判断 self.check_permissions(request) #6.控制访问频率 self.check_throttles(request)（3）determine_version
def determine_version(self, request, *args, **kwargs): """ If versioning is being used, then determine any API version for the incoming request. Returns a two-tuple of (version, versioning_scheme) """ if self.versioning_class is None: return (None, None) scheme = self.versioning_class() return (scheme.determine_version(request, *args, **kwargs), scheme)（4）versioning_class
URLPathVersioning源码
class URLPathVersioning(BaseVersioning): """ To the client this is the same style as `NamespaceVersioning`. The difference is in the backend - this implementation uses Django's URL keyword arguments to determine the version. An example URL conf for two views that accept two different versions. urlpatterns = [ url(r'^(?P<version>[v1|v2]+)/users/$', users_list,), url(r'^(?P<version>[v1|v2]+)/users/(?P<pk>[0-9]+)/$', users_detail,) ] GET /1.0/something/ HTTP/1.1 Host: example.com Accept: application/json """ invalid_version_message = _('Invalid version in URL path.') def determine_version(self, request, *args, **kwargs): version = kwargs.get(self.version_param, self.default_version) if not self.is_allowed_version(version): raise exceptions.NotFound(self.invalid_version_message) return version def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra): if request.version is not None: kwargs = {} if (kwargs is None) else kwargs kwargs[self.version_param] = request.version return super(URLPathVersioning, self).reverse( viewname, args, kwargs, request, format, **extra )可以看到
（1）url配置
（2）determine_version
里面有个is_allowed_version，点进去可以看到一些基本参数 （继承BaseVersioning基类）
class BaseVersioning(object): #默认的版本 default_version = api_settings.DEFAULT_VERSION #允许的版本 allowed_versions = api_settings.ALLOWED_VERSIONS #默认参数（是version，比如你可以自定义为v） version_param = api_settings.VERSION_PARAM def determine_version(self, request, *args, **kwargs): msg = '{cls}.determine_version() must be implemented.' raise NotImplementedError(msg.format( cls=self.__class__.__name__ )) def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, **extra): return _reverse(viewname, args, kwargs, request, format, **extra) def is_allowed_version(self, version): if not self.allowed_versions: return True return ((version is not None and version == self.default_version) or (version in self.allowed_versions))