03 DRF-request对象和参数

1 oop知识补充

• __getattr__

  class Foo(object):
  	def __init__(self, name, age):
  		self.name = name
  		self.age = age
  
  	def show(self):
  		return 123
  
  	def __getattr__(self, item):
  		# 当访问该对象中不存在的成员时，会执行
  		print("--->", item)
  		return 999
  
  
  obj = Foo('lxx', 12)
  # print(obj.name)
  # print(obj.age)
  # print(obj.show())
  
  # 反射
  # v1 = getattr(obj, 'show', '')
  # print(v1)  # 取值或执行方法，第3个参数取不到时返回。
  
  print(obj.xxx)  # 触发__getattr__
  

• __getattribute__

  class Foo(object):
  	def __init__(self, name, age):
  		self.name = name
  		self.age = age
  
  	def show(self):
  		return 123
  
  	def __getattribute__(self, item):
  		# 不管访问的成员存不存在都会执行
  		print('--->', item)
  		# return 999
  
  
  obj = Foo('lxx', 12)  # {'name': 'lxx', 'age': 12}
  print(obj.name)  # 999
  print(obj.age)  # 999
  print(obj.xxx)  # 999
  # 只要执行 对象.xxxx 都会执行
  # - 对象中有值，返回
  # - 对象中无值，报错
  

应用：

class HttpRequest(object):
    def __init__(self):
        pass

    def v1(self):
        print("v1")

    def v2(self):
        print("v1")


class Request(object):
    def __init__(self, req, xx):
        self._request = req
        self.xx = xx

    def __getattr__(self, attr):
        try:
            return getattr(self._request, attr)
        except AttributeError:
            return self.__getattribute__(attr)


request = HttpRequest()
request.v1()
request.v2()

request = Request(request, 111)
request.v1()
request.v2()

2 request传参

url 请求传参传递

urlpatterns = [
    path('user/<int:v1>/', views.UserView.as_view()),
]

class UserView(APIView):
    def get(self, request, *args, **kwargs):  # 方式1接收
        print(self.args)
        return Response('返回成功.')

# ----------------------------------------------------------

class UserView(APIView):
    def get(self, request, v1):  # 方式2接收
        return Response('返回成功.')

urlpatterns = [
    re_path('user/(\d+)/', views.UserView.as_view()),
	re_path('edit/(?P<pid>\d+)/', views.UserView.as_view()),
]

class UserView(APIView):
    def get(self, request, pid):
        print(request.user)  # 当前登录的用户  --> 匿名用户
        print(request.auth)
        return Response('返回成功.')

3 源码分析

4 request对象

drf中的request其实是对请求的再次封装，其目的就是在原来的request对象基础中再进行封装一些drf中需要用到的值。