Django - Admin

一、admin组件使用

Django 提供了基于 web 的管理工具。

Django 自动管理工具是 django.contrib 的一部分。你可以在项目的 settings.py 中的 INSTALLED_APPS 看到它:

# Application definition

INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'app01.apps.App01Config',
]

django.contrib是一套庞大的功能集,它是Django基本代码的组成部分。

 

1. 激活管理工具:

通常我们在生成项目时会在 urls.py 中自动设置好,

from django.contrib import admin
from django.urls import path

urlpatterns = [
path('admin/', admin.site.urls),
]

 当这一切都配置好后,Django 管理工具就可以运行了。

 

2. 使用管理工具:

启动开发服务器,然后在浏览器中访问 http://127.0.0.1:8000/admin/,得到登陆界面,你可以通过命令 python manage.py createsuperuser 来创建超级用户。

为了让 admin 界面管理某个数据模型,我们需要先注册数据模型admin

from django.db import models

# Create your models here.

from django.contrib.auth.models import AbstractUser

class GF(models.Model):
    name = models.CharField(max_length=32)
    age = models.CharField(max_length=32)

    def __str__(self):
        return self.name

class UserInfo(AbstractUser):
    tel = models.CharField(max_length=32)

    gf = models.ManyToManyField("GF")


class Room(models.Model):
    """
    会议室表
    """
    caption = models.CharField(max_length=32)
    num = models.IntegerField()  # 容纳人数

    def __str__(self):
        return self.caption

class Book(models.Model):
    """
    会议室预订信息
    """
    user = models.ForeignKey("UserInfo", on_delete=models.CASCADE)
    room = models.ForeignKey("Room", on_delete=models.CASCADE)
    date = models.DateField()
    time_choice = (
        (1,'8:00'),
        (2,'9:00'),
        (3,'10:00'),
        (4,'11:00'),
        (5,'12:00'),
        (6,'13:00'),
        (7,'14:00'),
        (8,'15:00'),
        (9,'16:00'),
        (10,'17:00'),
        (11,'18:00'),
        (12,'19:00'),
        (13,'20:00'),
    )
    time_id = models.IntegerField(choices=time_choice)

    class Meta:
        unique_together = (
            ('room','date','time_id'),
        )

    def __str__(self):
        return str(self.user)+'预订了'+str(self.room)
models.py
from django.db import models

# Create your models here.




class Author(models.Model):

    name=models.CharField( max_length=32)
    age=models.IntegerField()


    def __str__(self):
        return self.name

class Publish(models.Model):

    name=models.CharField( max_length=32)
    email=models.EmailField()

    def __str__(self):
        return self.name


class Book(models.Model):

    title = models.CharField( max_length=32)
    publishDate=models.DateField()
    price=models.DecimalField(max_digits=5,decimal_places=2)

    publisher=models.ForeignKey(to="Publish")
    authors=models.ManyToManyField(to='Author')

    def __str__(self):
        return self.title
View Code

 

3. admin的定制:

在admin.py中只需要将Mode中的某个类注册,即可在Admin中实现增删改查的功能,如:

admin.site.register(models.UserInfo)

但是,这种方式比较简单,如果想要进行更多的定制操作,需要利用ModelAdmin进行操作,如:

方式一:
    class UserAdmin(admin.ModelAdmin):
        list_display = ('user', 'pwd',)
 
    admin.site.register(models.UserInfo, UserAdmin) 
     
 
方式二:
    @admin.register(models.UserInfo)             
    class UserAdmin(admin.ModelAdmin):
        list_display = ('user', 'pwd',)

 

ModelAdmin中提供了大量的可定制功能,如

 1. list_display,列表时,定制显示的列。

@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
    list_display = ('user', 'pwd', 'xxxxx')
 
    def xxxxx(self, obj):
        return "xxxxx"

2. list_display_links,列表时,定制列可以点击跳转。

@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
    list_display = ('user', 'pwd', 'xxxxx')
    list_display_links = ('pwd',)

3. list_filter,列表时,定制右侧快速筛选。

4. list_select_related,列表时,连表查询是否自动select_related

5. list_editable,列表时,可以编辑的列 

@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
    list_display = ('user', 'pwd','ug',)
    list_editable = ('ug',)

6. search_fields,列表时,模糊搜索的功能

@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
     
    search_fields = ('user', 'pwd')

7. date_hierarchy,列表时,对Date和DateTime类型进行搜索

@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
 
    date_hierarchy = 'ctime'

8  inlines,详细页面,如果有其他表和当前表做FK,那么详细页面可以进行动态增加和删除

复制代码
class UserInfoInline(admin.StackedInline): # TabularInline
    extra = 0
    model = models.UserInfo
 
 
class GroupAdminMode(admin.ModelAdmin):
    list_display = ('id', 'title',)
    inlines = [UserInfoInline, ]
复制代码

9 action,列表时,定制action中的操作

复制代码
@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
 
    # 定制Action行为具体方法
    def func(self, request, queryset):
        print(self, request, queryset)
        print(request.POST.getlist('_selected_action'))
 
    func.short_description = "中文显示自定义Actions"
    actions = [func, ]
 
    # Action选项都是在页面上方显示
    actions_on_top = True
    # Action选项都是在页面下方显示
    actions_on_bottom = False
 
    # 是否显示选择个数
    actions_selection_counter = True
复制代码

10 定制HTML模板

add_form_template = None
change_form_template = None
change_list_template = None
delete_confirmation_template = None
delete_selected_confirmation_template = None
object_history_template = None

11 raw_id_fields,详细页面,针对FK和M2M字段变成以Input框形式

@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
 
    raw_id_fields = ('FK字段', 'M2M字段',)

12  fields,详细页面时,显示字段的字段

@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
    fields = ('user',)

13 exclude,详细页面时,排除的字段

@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
    exclude = ('user',)

14  readonly_fields,详细页面时,只读字段

@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
    readonly_fields = ('user',)

15 fieldsets,详细页面时,使用fieldsets标签对数据进行分割显示

复制代码
@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
    fieldsets = (
        ('基本数据', {
            'fields': ('user', 'pwd', 'ctime',)
        }),
        ('其他', {
            'classes': ('collapse', 'wide', 'extrapretty'),  # 'collapse','wide', 'extrapretty'
            'fields': ('user', 'pwd'),
        }),
    )
复制代码

16 详细页面时,M2M显示时,数据移动选择(方向:上下和左右)

@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
    filter_vertical = ("m2m字段",) # 或filter_horizontal = ("m2m字段",)

17 ordering,列表时,数据排序规则

@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
    ordering = ('-id',)
    或
    def get_ordering(self, request):
        return ['-id', ]

18. radio_fields,详细页面时,使用radio显示选项(FK默认使用select)

radio_fields = {"ug": admin.VERTICAL} # 或admin.HORIZONTAL

19 form = ModelForm,用于定制用户请求时候表单验证

复制代码
from app01 import models
from django.forms import ModelForm
from django.forms import fields
 
 
class MyForm(ModelForm):
    others = fields.CharField()
 
    class Meta:
        model = models = models.UserInfo
        fields = "__all__"
 
@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
 
    form = MyForm
复制代码

20 empty_value_display = "列数据为空时,显示默认值"

复制代码
@admin.register(models.UserInfo)
class UserAdmin(admin.ModelAdmin):
    empty_value_display = "列数据为空时,默认显示"
 
    list_display = ('user','pwd','up')
 
    def up(self,obj):
        return obj.user
    up.empty_value_display = "指定列数据为空时,默认显示"
from django.contrib import admin

# Register your models here.

from .models import *

@admin.register(Book)
class BookConfig(admin.ModelAdmin):
    # list_display = ('__str__',)

    # 不能放 多对多 字段!
    list_display = ['id', 'user', 'room', 'date', 'time_id']
    list_display_links = ['user',]
    list_filter = ['user', 'room', 'date']  # 比较难
    list_editable = ['room']

    # The value of 'room' cannot be in both 'list_editable' and 'list_display_links'.

    date_hierarchy = "date"

    # 定制Action行为具体方法
    def func(self,request,queryset):
        print(self,request,queryset)
        queryset.update(date='2012-12-12')

    func.short_description = "批量初始化操作"

    actions = [func,]

    # fields = ['user','room']  # 只显示
    # exclude = ['user','room']  # 不显示

    readonly_fields = ['user', 'room']  # 只读

    # ordering = ['id','date', 'time_id']
    ordering = ['-date']


class UserConfig(admin.ModelAdmin):
    # list_display = ['username', 'tel', 'gf']
    """
      'list_display[2]' must not be a ManyToManyField.

    """
    list_display = ['username', 'tel']
    list_filter = ['gf','username']
    search_fields = ['username', 'tel', ]  # 只能放 普通字段

admin.site.register(UserInfo,UserConfig)
# admin.site.register(Book,admin_class=BookConfig)
admin.site.register(Room)
admin.site.register(GF)
admin.py
from django.contrib import admin

# Register your models here.

from .models import *




class BookInline(admin.StackedInline): # TabularInline
    extra = 0
    model = Book

class BookAdmin(admin.ModelAdmin):

    list_display = ("title",'publishDate', 'price',"foo","publisher")
    list_display_links = ('publishDate',"price")
    list_filter = ('price',)
    list_editable=("title","publisher")
    search_fields = ('title',)
    date_hierarchy = 'publishDate'
    preserve_filters=False

    def foo(self,obj):

        return obj.title+str(obj.price)



    # 定制Action行为具体方法
    def func(self, request, queryset):
        print(self, request, queryset)
        print(request.POST.getlist('_selected_action'))

    func.short_description = "中文显示自定义Actions"
    actions = [func, ]
    # Action选项都是在页面上方显示
    actions_on_top = True
    # Action选项都是在页面下方显示
    actions_on_bottom = False

    # 是否显示选择个数
    actions_selection_counter = True



    change_list_template="my_change_list_template.html"



class PublishAdmin(admin.ModelAdmin):
     list_display = ('name', 'email',)
     inlines = [BookInline, ]



admin.site.register(Book, BookAdmin) # 第一个参数可以是列表
admin.site.register(Publish,PublishAdmin)
admin.site.register(Author)
View Code

二、单例模式

单例模式(Singleton Pattern)是一种常用的软件设计模式,该模式的主要目的是确保某一个类只有一个实例存在当你希望在整个系统中,某个类只能出现一个实例时,单例对象就能派上用场。

比如,某个服务器程序的配置信息存放在一个文件中,客户端通过一个 AppConfig 的类来读取配置文件的信息。如果在程序运行期间,有很多地方都需要使用配置文件的内容,也就是说,很多地方都需要创建 AppConfig 对象的实例,这就导致系统中存在多个 AppConfig 的实例对象,而这样会严重浪费内存资源,尤其是在配置文件内容很多的情况下。事实上,类似 AppConfig 这样的类,我们希望在程序运行期间只存在一个实例对象。

在 Python 中,我们可以用多种方法来实现单例模式:

  • 使用模块
  • 使用 __new__
  • 使用装饰器(decorator)
  • 使用元类(metaclass)

 

1. 使用 __new__

为了使类只能出现一个实例,我们可以使用 __new__ 来控制实例的创建过程,代码如下:

复制代码
class Singleton(object):
    _instance = None
    def __new__(cls, *args, **kw):
        if not cls._instance:
            cls._instance = super(Singleton, cls).__new__(cls, *args, **kw)  
        return cls._instance  

class MyClass(Singleton):  
    a = 1
复制代码

在上面的代码中,我们将类的实例和一个类变量 _instance 关联起来,如果 cls._instance 为 None 则创建实例,否则直接返回 cls._instance

执行情况如下:

复制代码
>>> one = MyClass()
>>> two = MyClass()
>>> one == two
True
>>> one is two
True
>>> id(one), id(two)
(4303862608, 4303862608)
复制代码
class Person(object):

    def __init__(self,name,age):
        self.name = name
        self.age = age

alex = Person('alex',34)
egon = Person('egon',36)

# 单例模式,一个类允许 实例一个对象
# 为什么这么做,为了数据统一
# 类:封装数据的组织形式
# 例如 配置文件,可以写成一个类,单例



class Singleton(object):
    _instance = None
    def __new__(cls, *args, **kw):
        if not cls._instance:
            cls._instance = super(Singleton, cls).__new__(cls, *args, **kw)
        return cls._instance

class MyClass(Singleton):
    a = 1

one = MyClass()
one.a = 3

two = MyClass()
print(two.a)  # 3 同一块内存

print(one==two)
print(id(one),id(two))


class Singleton(object):
    _instance = None
    def __new__(cls, *args, **kwargs):
        if not cls._instance:
            cls._instance = super(Singleton,cls).__new__(cls,*args,**kwargs)
        return cls._instance

class MyClass(Singleton):
    a = 1

one = MyClass()
two = MyClass()
one.a=3
print(id(one),id(two))
print(two.a)
print(MyClass.mro())
单例模式

 

2. 使用模块

 其实,Python 的模块就是天然的单例模式,因为模块在第一次导入时,会生成 .pyc 文件,当第二次导入时,就会直接加载 .pyc 文件,而不会再次执行模块代码。因此,我们只需把相关的函数和数据定义在一个模块中,就可以获得一个单例对象了。如果我们真的想要一个单例类,可以考虑这样做:

# mysingleton.py

class My_Singleton(object):
    x = 12
    def foo(self):
        print(self.x)

my_singleton = My_Singleton()

print('ok')

将上面的代码保存在文件 mysingleton.py 中,然后这样使用:

from mysingleton import my_singleton
 
my_singleton.foo()
# # -*- coding:utf-8 -*-
#
from mysingleton import my_singleton
#
# # pyc 中间 临时文件
#
# # my_singleton.foo()
# print(id(my_singleton))
#
#
from mysingleton import my_singleton
#
#
# # 在找 不会加载 第二遍  去临时 pyc 拿
#
# # my_singleton.foo()
# print(id(my_singleton))
#
#
# from func import *
# foo()  #三个id 会一样吗?? 一样,一次程序的执行,
#
# """
# ok
# 2341951012992
# 2341951012992
# 2341951012992
# """
#
#
# """
# 12
# 2664635842288
# 12
# 2664635842288
#
# 为什么内存地址一样
#
# python 自己的玩法, python 在导模块 就执行代码
# """


from mysingleton import my_singleton,My_Singleton

a = My_Singleton()
b = My_Singleton()

print(id(a),id(b))
# 2306139672928 2306139673096
# 不一样,类实例化,
# 单例 是从模块里 哪一个实例对象

print(id(my_singleton),id(my_singleton))
# 2310426005856 2310426005856  一样,
main.py
from mysingleton import my_singleton

def foo():
    print(id(my_singleton))
func.py

 

注:python 自己的玩法, python 在导模块时,就执行代码;

 

三、admin源码解析

<1> 循环加载执行所有已经注册的app中的admin.py文件

def autodiscover():
    autodiscover_modules('admin', register_to=site)

<2> 执行代码

复制代码
#admin.py

class BookAdmin(admin.ModelAdmin): list_display = ("title",'publishDate', 'price')
admin.site.register(Book, BookAdmin)
admin.site.register(Publish)
复制代码

<3> admin.site  

这里应用的是一个单例模式,对于AdminSite类的一个单例模式,执行的每一个app中的每一个admin.site都是一个对象

<4> 执行register方法

admin.site.register(Book, BookAdmin) 
admin.site.register(Publish)
复制代码
class ModelAdmin(BaseModelAdmin):pass

def register(self, model_or_iterable, admin_class=None, **options):
    if not admin_class:
            admin_class = ModelAdmin
    # Instantiate the admin class to save in the registry
    self._registry[model] = admin_class(model, self)
复制代码

思考:在每一个app的admin .py中加上

print(admin.site._registry)   # 执行结果?

到这里,注册结束!

<5> admin的URL配置

urlpatterns = [
    url(r'^admin/', admin.site.urls),
]
复制代码
class AdminSite(object):
    
     def get_urls(self):
        from django.conf.urls import url, include
      
        urlpatterns = []

        # Add in each model's views, and create a list of valid URLS for the
        # app_index
        valid_app_labels = []
        for model, model_admin in self._registry.items():
            urlpatterns += [
                url(r'^%s/%s/' % (model._meta.app_label, model._meta.model_name), include(model_admin.urls)),
            ]
            if model._meta.app_label not in valid_app_labels:
                valid_app_labels.append(model._meta.app_label)

      
        return urlpatterns

    @property
    def urls(self):
        return self.get_urls(), 'admin', self.name
复制代码

<6>  url()方法的扩展应用

复制代码
from django.shortcuts import HttpResponse
def test01(request):
    return HttpResponse("test01")

def test02(request):
    return HttpResponse("test02")

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^yuan/', ([
                    url(r'^test01/', test01),
                    url(r'^test02/', test02),

                    ],None,None)),

]
复制代码

扩展优化

复制代码
from django.conf.urls import url,include
from django.contrib import admin

from django.shortcuts import HttpResponse

def change_list_view(request):
    return HttpResponse("change_list_view")
def add_view(request):
    return HttpResponse("add_view")
def delete_view(request):
    return HttpResponse("delete_view")
def change_view(request):
    return HttpResponse("change_view")

def get_urls():

    temp=[
        url(r"^$".format(app_name,model_name),change_list_view),
        url(r"^add/$".format(app_name,model_name),add_view),
        url(r"^\d+/del/$".format(app_name,model_name),delete_view),
        url(r"^\d+/change/$".format(app_name,model_name),change_view),
    ]

    return temp


url_list=[]

for model_class,obj in admin.site._registry.items():

    model_name=model_class._meta.model_name
    app_name=model_class._meta.app_label

    # temp=url(r"{0}/{1}/".format(app_name,model_name),(get_urls(),None,None))
    temp=url(r"{0}/{1}/".format(app_name,model_name),include(get_urls()))
    url_list.append(temp)

urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^yuan/', (url_list,None,None)),
]
复制代码

 https://www.cnblogs.com/yuanchenqi/articles/8323452.html 

权限
会议室预订
admin与stark  admin怎么用,怎么写?
1.admin 不够灵活,不知怎么写,没法扩展!!
2.stark怎么用 看源码 怎么去利用 构建自己的架构!!
stark 难点!!
用一个类 来实现? 封装 继承 多态 一堆 面向 面向对象

重点:面向对象,网络编程,web应用
迭代器生成器,python独有的!!数据库!

admin
使用,再看源码!!
stark
crm
restframework 3-4
vue 3-4
路飞
爬虫,linux flask

----------------------------------

知识点1:

    url()的使用

    情况1:url(r'^book/', views.book),  # book(request)

    情况2 分发:
    url(r"^yuan/", ([
                        url(r'^test01/', ([
                                              url(r'^test04/', test04),
                                              url(r'^test05/', test05),
                                          ], None, None)),
                        url(r'^test02/', test02),
                        url(r'^test03/', test03),
                    ], None, None)
        )

知识点2:

    单例模式
        生成单例模式的方式:
        (1)使用 __new__2)使用模块
             class A()
                pass
             a=A()

admin源码:

1 注册 admin.py

    admin.site.register(Book,BookConfig)

    源码:

        class AdminSite():
             def __init__(self, name='admin'):
                 self._registry = {}

             def register(self,model,admin_class):
                 if not admin_class:
                      admin_class = ModelAdmin

                 self._registry[model] = admin_class(model, self)



        site=AdminSite()



2 设计url

    如何通过model类变量获取该模型的字符串名称和该模型所在app的字符串名称:
    print("===>", model._meta.model_name)
    print("===>", model._meta.app_label)
    
###################################################################



def add(request):
    return HttpResponse("add")
def delete(request,id):
    return HttpResponse("delete")
def change(request,id):
    return HttpResponse("change")
def list_view(request):
    return HttpResponse("list_view")


def get_urls2():

    temp=[]
    temp.append(url(r"^add/",add))
    temp.append(url(r"^(\d+)/delete/",delete))
    temp.append(url(r"^(\d+)/change/",change))
    temp.append(url(r"^$",list_view))
    return temp

def get_urls():


    temp=[]
    print("_registry",admin.site._registry)

    for model,admin_class_obj in admin.site._registry.items():
         print("model",model) # 所有的注册模型表

         # < class 'app01.models.Book'>----->     "book"  "app01"
         # < class 'app01.models.Room'>----->     "room"  "app01"
         # print("===>",model._meta.model_name)
         # print("===>",model._meta.app_label)

         model_name=model._meta.model_name
         app_label=model._meta.app_label
         temp.append(url(r"%s/%s/"%(app_label,model_name),(get_urls2(),None,None)))

    return temp



urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^index/', views.index),
    url(r'^login/', views.login),
    url(r'^book/', views.book),


    url(r"^yuan/",(get_urls(),None,None))


]


上节回顾

1   admin的使用
    list_display
    list_display_links
    search_fields
    list_filter
    action

    class BookConfig(admin.ModelAdmin):
        list_display
        list_display_links
        search_fields
        list_filter
        action
    admin.site.register(Book,BookConfig)

2   知识点

    url()的使用

    情况1:url(r'^book/', views.book),  # book(request)

    情况2 分发:
    url(r"^yuan/", ([
                       url(r'^test01/', ([
                                             url(r'^test04/', test04),
                                             url(r'^test05/', test05),
                                         ], None, None)),
                       url(r'^test02/', test02),
                       url(r'^test03/', test03),
                   ], None, None)
       )

    单例模式
       生成单例模式的方式:
       (1)使用 __new__2)使用模块
            class A()
               pass
            a=A()

            admin源码:
            1 启动文件
            class StarkConfig(AppConfig):
               name = 'stark'
               def ready(self):
                   autodiscover_modules('stark')

            2 注册 admin.py

                admin.site.register(Book,BookConfig)

                源码:

                    class AdminSite():
                         def __init__(self, name='admin'):
                             self._registry = {}

                         def register(self,model,admin_class):
                             if not admin_class:
                                  admin_class = ModelAdmin

                             self._registry[model] = admin_class(model, self)

                    site=AdminSite()

            3 设计url

                如何通过model类变量获取该模型的字符串名称和该模型所在app的字符串名称:
                print("===>", model._meta.model_name)
                print("===>", model._meta.app_label)

在ModelStark中:
       self.model: 用户当前访问的模型表

 查看页面:
      表头
      表数据
      search
      action
      分页
      filter

  增删改(modelForm)

   pop

   作业1:

       访问任何模型时都有编辑,删除,选择
   作业2:
       如果用户没有配置list_display,显示对象
    作业3:
        名称空间
笔记

四、admin - 知识点

1.知识点1:
url()的使用:

情况1:path('book/', views.book), # book(request)
情况2:分发:
path('yuan/',yuan), # yuan
path('yuan/',([],None,None)) # None,None 代表:namespace app(name)
path('yuan/',([path('test01/',test01)],None,None)), # yuan/test01

        path('yuan/',([
                path('test01/',([
                    path('test04/',test04),                        # yuan/test01/test04
                    path('test05/',test05)                         # yuan/test01/test05
                                ],None,None)),
                path('test02/',test02),                            # yuan/test02
                path('test03/',test03)                             # yuan/test03
                            ],None,None))    
    
注: re_path(r'^test04/',test04), # 以test04开头;
re_path(r'test04/',test04), # 包含test04;

2.知识点2:
单例模式

生成单例模式的方式:
(1)使用 __new__
        class Singleton(object):
                _instance = None
                def __new__(cls, *args, **kw):
                    if not cls._instance:
                        cls._instance = super(Singleton, cls).__new__(cls, *args, **kw)  
                    return cls._instance  
            
            class MyClass(Singleton):  
                a = 1
            
            >>> one = MyClass()
            >>> two = MyClass()
            >>> one == two
            True
 
        (2)使用模块
            class My_Singleton(object):
                x = 12
                def foo(self):
                    print(self.x)
                
            my_singleton = My_Singleton()
        
        
            from mysingleton import my_singleton
            my_singleton.foo()
 
3.知识点3:
admin源码:

1.注册 admin.py
from django.contrib import admin

class BookConfig(admin.ModelAdmin):
list_display = ['user', 'room']
...

admin.site.register(Book,BookConfig) # admin.site 就是 AdminSite()的一个实例化对象单例
admin.site.register(UserInfo,UserConfig)
admin.site.register(Room)

        class AdminSite():
            def __init__(self, name='admin'):
                self._registry = {}
            
            def register(self, model, admin_class=None):
                if not admin_class:
                    admin_class = ModelAdmin
            
                self._registry[model] = admin_class(model, self)

        ...
        ...
        site = AdminSite()

所以:按顺序注册后,结果都在 admin.site._registry 字典里面;model为键,admin_class(model, self)为值
即:Book为键,BookConfig()为值;
UserInfo为键,UserConfig()为值;
Room为键,ModelAdmin()为值;

注意:admin.site._registry 全局的!! 多个app共用!!(startapp02)
     print(admin.site._registry)
            {<class 'django.contrib.auth.models.Group'>: <django.contrib.auth.admin.GroupAdmin object at 0x000002777731D400>,
            <class 'app01.models.Book'>: <app01.admin.BookConfig object at 0x000002777735C470>,
            <class 'app01.models.UserInfo'>: <app01.admin.UserConfig object at 0x000002777735C4A8>,
            <class 'app01.models.Room'>: <django.contrib.admin.options.ModelAdmin object at 0x000002777735C4E0>,
            <class 'app01.models.GF'>: <django.contrib.admin.options.ModelAdmin object at 0x000002777735C518>,
            <class 'app02.models.Book'>: <django.contrib.admin.options.ModelAdmin object at 0x000002777735C438>}

2.设计 url:
注意:
1.
path('yuan/',(get_urls(),None,None)),
path('yuan/',include(get_urls()))

2.
for model,admin_class_obj in admin.site._registry.items():
print('****',model) # **** <class 'app01.models.Book'>

model_name = model._meta.model_name # book
app_label = model._meta.app_label # app01

3.
temp.append(path('%s/%s/'%(app_label,model_name),(get_urls2(),None,None)))

4.
temp.append(path('add/',add))
temp.append(re_path(r'(\d+)/delete/',delete))
temp.append(re_path(r'(\d+)/change/',change))
temp.append(re_path(r'^$',list_view))

5.
# 24条 url 。。。
# http://127.0.0.1:8020/yuan/app01/book/
# http://127.0.0.1:8020/yuan/app01/userinfo/add/
# http://127.0.0.1:8020/yuan/app01/book/5/delete/
# http://127.0.0.1:8020/yuan/app02/book/
。。。
。。。

        def add(request):
            return HttpResponse('add')
        
        def delete(request,del_id):
            return HttpResponse('delete')
        
        def change(request,change_id):
            return HttpResponse('change')
        
        def list_view(request):
            return HttpResponse('list_view')
        
        
        def get_urls2():
            temp = []
            temp.append(path('add/',add))
            temp.append(re_path(r'(\d+)/delete/',delete))
            temp.append(re_path(r'(\d+)/change/',change))
            temp.append(re_path(r'^$',list_view))
            return temp
        
        def get_urls():
            temp = []
            print('_registry:',admin.site._registry)
            for model,admin_class_obj in admin.site._registry.items():
                print('****',model)
               
                # **** <class 'django.contrib.auth.models.Group'>
                # **** <class 'app01.models.Book'>
           # ... ...
                # **** <class 'app02.models.Book'>
                
        
                model_name = model._meta.model_name  # book
                app_label = model._meta.app_label   # app01
        
                temp.append(path('%s/%s/'%(app_label,model_name),(get_urls2(),None,None)))
                
                # http://127.0.0.1:8020/yuan/app01/book/
                # http://127.0.0.1:8020/yuan/app01/book/add/
     
            # ... ...   
                # http://127.0.0.1:8020/yuan/app02/book/
        
                # 24条  url 。。。
            
            return temp

            urlpatterns = [
                path('admin/', admin.site.urls),
                path('yuan/',(get_urls(),None,None)),
                # path('yuan/',include(get_urls()))
            ]

 

from django.contrib import admin
from django.urls import path,re_path,include

from app01 import views
from django.shortcuts import HttpResponse

def yuan(request):
    return HttpResponse('yuan')

def test01(request):
    return HttpResponse('test01')

def test02(request):
    return HttpResponse('test02')

def test03(request):
    return HttpResponse('test03')

def test04(request):
    return HttpResponse('test04')

def test05(request):
    return HttpResponse('test05')


def add(request):
    return HttpResponse('add')

def delete(request,del_id):
    return HttpResponse('delete')

def change(request,change_id):
    return HttpResponse('change')

def list_view(request):
    return HttpResponse('list_view')


def get_urls2():
    temp = []
    temp.append(path('add/',add))
    temp.append(re_path(r'(\d+)/delete/',delete))
    temp.append(re_path(r'(\d+)/change/',change))
    temp.append(re_path(r'^$',list_view))
    return temp

def get_urls():
    temp = []
    print('_registry:',admin.site._registry)
    for model,admin_class_obj in admin.site._registry.items():
        print('****',model)
        """
            **** <class 'django.contrib.auth.models.Group'>
            **** <class 'app01.models.Book'>
            **** <class 'app01.models.UserInfo'>
            **** <class 'app01.models.Room'>
            **** <class 'app01.models.GF'>
            **** <class 'app02.models.Book'>
        """

        model_name = model._meta.model_name  # book
        app_label = model._meta.app_label   # app01

        temp.append(path('%s/%s/'%(app_label,model_name),(get_urls2(),None,None)))
        # yuan/app01/book/
        # http://127.0.0.1:8020/yuan/app01/book/
        # http://127.0.0.1:8020/yuan/app01/book/add/
        # http://127.0.0.1:8020/yuan/app01/userinfo/add/

        # http://127.0.0.1:8020/yuan/app01/book/5/delete/
        # http://127.0.0.1:8020/yuan/app01/userinfo/4/delete/

        # http://127.0.0.1:8020/yuan/app01/book/5/change/

        # http://127.0.0.1:8020/yuan/app02/book/

        # 24条 条 url 。。。
    return temp

# get_urls()

urlpatterns = [
    path('admin/', admin.site.urls),
    path('login/', views.login),
    path('index/', views.index),
    path('book/', views.book),

    # path('yuan/',yuan),
    # path('yuan/',([path('test01/',test01)],None,None)),
    #
    # path('yuan/',([
    #     path('test01/',([
    #         path('test04/',test04),
    #         path('test05/',test05)
    #                     ],None,None)),
    #     path('test02/',test02),
    #     path('test03/',test03)
    #                 ],None,None))

    # path('yuan/',([
    #       path('test01/',([
    #           re_path(r'^test04/',test04), # # http://127.0.0.1:8000/yuan/test01/test04/
    #           # re_path(r'test04/',test04), # http://127.0.0.1:8000/yuan/test01/abc/test04/ 这样也可以,只要后面包含test04
    #           path('test05/',test05), # http://127.0.0.1:8000/yuan/test01/test05/
    #                       ],None,None)),    # http://127.0.0.1:8000/yuan/test01/
    #       path('test02/',test02),    # http://127.0.0.1:8000/yuan/test02/
    #       path('test03/',test03),    # http://127.0.0.1:8000/yuan/test03/
    #   ],None,None)),  # None,None namespace  app  是两个名字!!


    path('yuan/',(get_urls(),None,None)),
    # path('yuan/',include(get_urls()))

]
urls.py
posted @ 2018-06-17 14:13  Alice的小屋  阅读(314)  评论(0编辑  收藏  举报