一：登录操作
from django.contrib.auth import authenticate,login,logout #可以用来做登录验证
from django.contrib.auth.decorators import login_required #装饰器，用于对用户是否登录进行验证
1.简单使用：
def acc_login(request):
error_msg = ''
if request.method == "POST":
username = request.POST.get("username")
password = request.POST.get("password")
user = authenticate(username=username,password=password) #进行用户验证
if user:
login(request,user) #登录状态，添加入session, request.user = user
return redirect(request.GET.get("next","/"))
else:
error_msg = "Wrong Username Or Password"
return render(request,"login.html",{"error_msg":error_msg})
def acc_logout(request):
logout(request) #清除session数据
return redirect("/login.html")
from django.contrib.auth.decorators import login_required
@login_required
def dashboard(request):
return render(request,"Sale/dashboard.html")
注意：使用@login_required需要我们配置
LOGIN_URL = "/login.html" #默认是在accounts/login路由下跳转
2.方法了解
（1）authenticate方法
def authenticate(self, request, username=None, password=None, **kwargs):
if username is None:
username = kwargs.get(UserModel.USERNAME_FIELD)
try:
user = UserModel._default_manager.get_by_natural_key(username) #根据用户名获取用户对象
except UserModel.DoesNotExist:
# Run the default password hasher once to reduce the timing
# difference between an existing and a non-existing user (#20760).
UserModel().set_password(password)
else:
if user.check_password(password) and self.user_can_authenticate(user): #根据密码进行登录验证，以及获取用户的操作权限
return user
UserModel = get_user_model()
def get_user_model(): #返回用户表对象，对象由AUTH_USER_MODEL指定，默认是auth.User默认数据表，我们可以在自己的setting文件中进行覆盖
"""
Returns the User model that is active in this project.
"""
return django_apps.get_model(settings.AUTH_USER_MODEL, require_ready=False)
（2）login方法
def login(request, user, backend=None):
def login(request, user, backend=None):
"""
Persist a user id and a backend in the request. This way a user doesn't
have to reauthenticate on every request. Note that data set during
the anonymous session is retained when the user logs in.
"""
session_auth_hash = ''
if user is None:
user = request.user
if hasattr(user, 'get_session_auth_hash'):
session_auth_hash = user.get_session_auth_hash()
if SESSION_KEY in request.session:
if _get_user_session_key(request) != user.pk or (
session_auth_hash and
not constant_time_compare(request.session.get(HASH_SESSION_KEY, ''), session_auth_hash)):
# To avoid reusing another user's session, create a new, empty
# session if the existing session corresponds to a different
# authenticated user.
request.session.flush()
else:
request.session.cycle_key()
try:
backend = backend or user.backend
except AttributeError:
backends = _get_backends(return_tuples=True)
if len(backends) == 1:
_, backend = backends[0]
else:
raise ValueError(
'You have multiple authentication backends configured and '
'therefore must provide the `backend` argument or set the '
'`backend` attribute on the user.'
)
request.session[SESSION_KEY] = user._meta.pk.value_to_string(user)
request.session[BACKEND_SESSION_KEY] = backend
request.session[HASH_SESSION_KEY] = session_auth_hash
if hasattr(request, 'user'):
request.user = user
rotate_token(request)
user_logged_in.send(sender=user.__class__, request=request, user=user)
设置session,向request中添加user属性，可以直接使用request.user获取User表对象（3）logout方法
def logout(request):
"""
Removes the authenticated user's ID from the request and flushes their
session data.
"""
# Dispatch the signal before the user is logged out so the receivers have a
# chance to find out *who* logged out.
user = getattr(request, 'user', None)
if hasattr(user, 'is_authenticated') and not user.is_authenticated:
user = None
user_logged_out.send(sender=user.__class__, request=request, user=user)
# remember language choice saved to session
language = request.session.get(LANGUAGE_SESSION_KEY)
request.session.flush()
if language is not None:
request.session[LANGUAGE_SESSION_KEY] = language
if hasattr(request, 'user'):
from django.contrib.auth.models import AnonymousUser
request.user = AnonymousUser()
清空session，删除request.user
（4）login_required方法
def login_required(function=None, redirect_field_name=REDIRECT_FIELD_NAME, login_url=None):#function是我们装饰的函数名，redirect_field_name是跳转时所带的参数，默认next
"""
Decorator for views that checks that the user is logged in, redirecting
to the log-in page if necessary.
"""
actual_decorator = user_passes_test(
lambda u: u.is_authenticated,
login_url=login_url,
redirect_field_name=redirect_field_name
)
if function:
return actual_decorator(function)
return actual_decorator
函数体
def user_passes_test(test_func, login_url=None, redirect_field_name=REDIRECT_FIELD_NAME):
"""
Decorator for views that checks that the user passes the given test,
redirecting to the log-in page if necessary. The test should be a callable
that takes the user object and returns True if the user passes.
"""
def decorator(view_func):
@wraps(view_func, assigned=available_attrs(view_func))
def _wrapped_view(request, *args, **kwargs):
if test_func(request.user):
return view_func(request, *args, **kwargs)
path = request.build_absolute_uri()
resolved_login_url = resolve_url(login_url or settings.LOGIN_URL)
# If the login url is the same scheme and net location then just
# use the path as the "next" url.
login_scheme, login_netloc = urlparse(resolved_login_url)[:2]
current_scheme, current_netloc = urlparse(path)[:2]
if ((not login_scheme or login_scheme == current_scheme) and
(not login_netloc or login_netloc == current_netloc)):
path = request.get_full_path()
from django.contrib.auth.views import redirect_to_login
return redirect_to_login(
path, resolved_login_url, redirect_field_name)
return _wrapped_view
return decorator
装饰器方法
二：csrf的多种使用方法
from django.views.decorators.csrf import csrf_exempt
1.需求分析
当我们需要对某一个view方法去掉csrf_token验证时。总不至于去注释掉所有的csrf验证吧
# 'django.middleware.csrf.CsrfViewMiddleware',
那么我们需要去取消某一个方法的csrf验证
2.实现代码
1.FBV:直接使用装饰器方法
@csrf_exempt
def asset(request):
pass
2.CBV:需要再去引入一个模块（其实也可以直接使用）
from django.utils.decorators import method_decorator
class AssetView(View):
@method_decorator(csrf_exempt)
def dispatch(self, request, *args, **kwargs):
return super(AssetView, self).dispatch(request, *args, **kwargs)
def post(self,request,*args,**kwargs):
pass
def put(self,request,*args,**kwargs):
pass
其中dispatch()方法：作用是将任务分发到正确的方法上。因为需要过滤掉csrf的方法不止post，还有put等，所以在dispatch中过滤掉csrf，那么在其他的方法上可以不用去管
3.在url中进行过滤
from django.conf.urls import url
from API import views as v1
from django.views.decorators.csrf import csrf_exempt
urlpatterns = [
url(r'^asset',csrf_exempt(v1.AssetView.as_view())),
]
三：import导入的多种方法（用于反射）
1.一般导入模块直接使用import
import 模块 #一般我们是直接使用import导入对应模块
from 包 import 模块 #多层导入
2.需求：现有字符串代表各个模块，如何通过反射获取该模块
（1）使用__import__
__import__("模块")
__import__("层一.层二.层三.模块",fromlist=True) #对于多层，我们使用.连接。注意：fromlist需要添加为True，不然只会导入层一，调用的使用我们还要一级一级向下找，不方便
def __import__(name, globals=None, locals=None, fromlist=(), level=0): # real signature unknown; restored from __doc__
When importing a module from a package, note that __import__('A.B', ...)
returns package A when fromlist is empty, but its submodule B when
fromlist is not empty.
package：test3 ---> 包下面有t2.py文件，定义test2方法
无fromlist:
md = __import__("test3.t2")
md.t2.test2() #test2
有fromlist
md = __import__("test3.t2",fromlist=True)
md.test2()
演示结果
（2）使用importlib.import_module
def import_module(name, package=None):
#如果是相对导入的话，第二个参数是需要的
The 'package' argument is required when performing a relative import. It
specifies the package to use as the anchor point from which to resolve the
relative import to an absolute import.
md = importlib.import_module("test3.t2")
md.test2() #test2
md = importlib.import_module(".t2","test3") #.t2代表时相对于test3下的相对路径，就是相当于将前后连接test3.t2
md.test2()
md = importlib.import_module("test3.t1.t11")
md.test11()
md = importlib.import_module(".t1.t11","test3")
md.test11()
#test11
#test11
再多一级