Django 提供了基於 web 的管理工具。python
Django 自動管理工具是 django.contrib 的一部分。你能夠在項目的 settings.py 中的 INSTALLED_APPS 看到它:git
# Application definition INSTALLED_APPS = [ 'django.contrib.admin', 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.messages', 'django.contrib.staticfiles', "app01" ]
django.contrib是一套龐大的功能集,它是Django基本代碼的組成部分。 web
一般咱們在生成項目時會在 urls.py 中自動設置好,django
from django.conf.urls import url from django.contrib import admin urlpatterns = [ url(r'^admin/', admin.site.urls), ] from django.contrib import admin from django.urls import path urlpatterns = [ path('admin/', admin.site.urls), ]
當這一切都配置好後,Django 管理工具就能夠運行了。設計模式
啓動開發服務器,而後在瀏覽器中訪問 http://127.0.0.1:8000/admin/,獲得登錄界面,你能夠經過命令 python manage.py createsuperuser 來建立超級用戶。瀏覽器
爲了讓 admin 界面管理某個數據模型,咱們須要先註冊該數據模型到 admin服務器
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
在admin.py中只須要講Model中的某個類註冊,便可在Admin中實現增刪改查的功能,如:session
from django.contrib import admin from app01.models import * admin.site.register(UserInfo) admin.site.register(Book) admin.site.register(Room)
可是,這種方式比較簡單,若是想要進行更多的定製操做,須要利用ModelAdmin進行操做,如:app
方式一: class UserAdmin(admin.ModelAdmin): list_display = ('user', 'pwd',) admin.site.register(models.UserInfo, UserAdmin) # 第一個參數能夠是列表 方式二: @admin.register(models.UserInfo) # 第一個參數能夠是列表 class UserAdmin(admin.ModelAdmin): list_display = ('user', 'pwd',)
ModelAdmin中提供了大量的可定製功能,如ide
# 模板 @admin.register(models.UserInfo) class UserAdmin(admin.ModelAdmin): list_display = ('user', 'pwd', 'xxxxx') def xxxxx(self, obj): return "xxxxx"
在MRBS系統上定製admin示例:
class BookConfig(admin.ModelAdmin): list_display = ["user", "room", "date"] # 不能放多對多字段 admin.site.register(Book, BookConfig) # 定製類繼承了ModelAdmin, 但優先顯示BookConfig類的,找不到再找父類的
顯示效果:
class BookConfig(admin.ModelAdmin): list_display = ["user", "room", "date"] # 不能放多對多字段 list_display_links = ["room", "date"] # 自由定製哪一列能夠作跳轉 admin.site.register(Book, BookConfig)
顯示效果:
class BookConfig(admin.ModelAdmin): list_display = ["user", "room", "date"] # 不能放多對多字段 list_display_links = ["room", "date"] # 自由定製哪一列能夠作跳轉 list_filter = ["user", "date"] # 定製右側快速篩選 admin.site.register(Book, BookConfig)
顯示效果:
class BookConfig(admin.ModelAdmin): list_display = ["user", "room", "date"] # 不能放多對多字段 list_display_links = ["room", "date"] # 自由定製哪一列能夠作跳轉 list_filter = ["user", "date"] # 定製右側快速篩選 list_editable = ["user"] admin.site.register(Book, BookConfig)
須要注意的是設置爲list_editable就不能設置爲list_display_links。
顯示效果
@admin.register(models.UserInfo) class UserAdmin(admin.ModelAdmin): search_fields = ('user', 'pwd')
顯示效果:
class BookConfig(admin.ModelAdmin): list_display = ["user", "room", "date"] # 不能放多對多字段 list_display_links = ["room", "date"] # 自由定製哪一列能夠作跳轉 list_filter = ["user", "date"] # 定製右側快速篩選 list_editable = ["user"] search_fields = ['date'] date_hierarchy = 'date' admin.site.register(Book, BookConfig)
顯示效果:
class UserInfoInline(admin.StackedInline): # TabularInline extra = 0 model = models.UserInfo class GroupAdminMode(admin.ModelAdmin): list_display = ('id', 'title',) inlines = [UserInfoInline, ]
自帶的action操做是一個批量選中刪除的操做:
點擊go即完成刪除操做。
自定製action的操做:
class BookConfig(admin.ModelAdmin): ... # 定製Action行爲具體方法 def func(self, request, queryset): print(self, request, queryset) queryset.update(date="2012-12-12") func.short_description = "批量初始化操做" actions = [func, ] # Action選項都是在頁面上方顯示 actions_on_top = True # Action選項都是在頁面下方顯示 actions_on_bottom = False # 是否顯示選擇個數 actions_selection_counter = True admin.site.register(Book, BookConfig)
點選並選擇批量初始化後,顯示效果以下:
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
@admin.register(models.UserInfo) class UserAdmin(admin.ModelAdmin): raw_id_fields = ('FK字段', 'M2M字段',)
添加頁面原始顯示:
修改了添加頁面的顯示字段:
class BookConfig(admin.ModelAdmin): ... fields = ['user', ]
修改後顯示效果:
class BookConfig(admin.ModelAdmin): ... # fields = ['user', ] exclude = ['user', 'room']
與fields相反,排除哪些字段不顯示,顯示效果以下:
@admin.register(models.UserInfo) class UserAdmin(admin.ModelAdmin): readonly_fields = ('user',)
@admin.register(models.UserInfo) class UserAdmin(admin.ModelAdmin): fieldsets = ( ('基本數據', { 'fields': ('user', 'pwd', 'ctime',) }), ('其餘', { 'classes': ('collapse', 'wide', 'extrapretty'), # 'collapse','wide', 'extrapretty' 'fields': ('user', 'pwd'), }), )
@admin.register(models.UserInfo) class UserAdmin(admin.ModelAdmin): filter_vertical = ("m2m字段",) # 或filter_horizontal = ("m2m字段",)
class BookConfig(admin.ModelAdmin): list_display = ["id", "user", "room", "date"] # 不能放多對多字段 ordering = ["id"]
添加「id」字段顯示,並進行排序,顯示以下:
在添加的字段前加「-」,便是反向排序:
class BookConfig(admin.ModelAdmin): ordering = ['-date'] # 反向排序
ordering = []中能夠添加多個字段,但不是聯合排序,而是在第一個字段排序相同的狀況下,按第二個字段排序。
class BookConfig(admin.ModelAdmin): ordering = ['-date', "time_id"]
radio_fields = {"ug": admin.VERTICAL} # 或admin.HORIZONTAL
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
@admin.register(models.UserInfo) class UserAdmin(admin.ModelAdmin): empty_value_display = "列數據爲空時,默認顯示" list_display = ('user','pwd','up') def up(self,obj): return obj.user up.empty_value_display = "指定列數據爲空時,默認顯示"
單例模式(Singleton Pattern)是一種經常使用的軟件設計模式,該模式的主要目的是確保某一個類只有一個實例存在。當你但願在整個系統中,某個類只能出現一個實例時,單例對象就能派上用場。
好比,某個服務器程序的配置信息存放在一個文件中,客戶端經過一個 AppConfig 的類來讀取配置文件的信息。若是在程序運行期間,有不少地方都須要使用配置文件的內容,也就是說,不少地方都須要建立 AppConfig 對象的實例,這就致使系統中存在多個 AppConfig 的實例對象,而這樣會嚴重浪費內存資源,尤爲是在配置文件內容不少的狀況下。事實上,相似 AppConfig 這樣的類,咱們但願在程序運行期間只存在一個實例對象。
在 Python 中,咱們能夠用多種方法來實現單例模式:
__new__
爲了使類只能出現一個實例,咱們可使用 __new__
來控制實例的建立過程,代碼以下:
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) print("one", id(one)) print("tow", id(two)) """ 3 one 4362186704 tow 4362186704 """
在上面的代碼中,咱們將類的實例和一個類變量 _instance
關聯起來,若是 cls._instance
爲 None 則建立實例,不然直接返回 cls._instance
。
經過執行狀況能夠看到,建立的兩個實例內存地址相同,實際上是一個對象。所以第一個對象修改a的值後,建立第二對象其實只是指向這個內存地址,a的值也是被修改過的。
其實,Python 的模塊就是自然的單例模式,由於模塊在第一次導入時,會生成 .pyc
文件,當第二次導入時,就會直接加載 .pyc
文件,而不會再次執行模塊代碼。所以,咱們只需把相關的函數和數據定義在一個模塊中,就能夠得到一個單例對象了。
mysingleton.py:
class My_Singleton(object): x = 12 def foo(self): print(self.x) my_singleton = My_Singleton() print("OK")
main.py:
from mysingleton import my_singleton print(id(my_singleton)) from mysingleton import my_singleton print(id(my_singleton)) """ OK 4366742976 4366742976 """
注意這裏的導入的不是類仍是實例對象。
這裏只打印了一次「OK」,這是由於第一次導入模塊的時,就已經將代碼執行了一遍。加載過程當中生成了一個.pyc中間文件。將執行中拿到變量放到.pyc文件中。再一次導入模塊時,再也不執行代碼,而是直接去.pyc文件中存好的實例對象中拿取變量。
mysingleton.py:
class My_Singleton(object): x = 12 def foo(self): print(self.x) my_singleton = My_Singleton() print("OK")
func.py:
from mysingleton import my_singleton def foo(): print(id(my_singleton))
main.py:
from mysingleton import my_singleton print(id(my_singleton)) from mysingleton import my_singleton print(id(my_singleton)) from func import * foo() """ OK 4362186536 4362186536 4362186536 """
一個程序無論導入的形式如何變換,仍是從同一個.pyc文件中去取。
程序跑起來後,導入一次後,只要仍是程序過程當中,其餘地方的導入拿到的實例對象和以前那個實例對象是一個對象。
def autodiscover(): autodiscover_modules('admin', register_to=site)
#admin.py class BookAdmin(admin.ModelAdmin): list_display = ("title",'publishDate', 'price') admin.site.register(Book, BookAdmin) admin.site.register(Publish)
這裏應用的是一個單例模式,對於AdminSite類的一個單例模式,執行的每個app中的每個admin.site都是一個對象
admin.site.register(Book, BookAdmin) admin.site.register(Publish)
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)
思考:在每個app的admin .py中加上
print(admin.site._registry) # 執行結果?
在一個程序裏,只要用到admin.site無論在幾個app中都是一個對象。所以admin.site._registry執行結果都是獲得全部的註冊對象。
到這裏,註冊結束!
urlpatterns = [ url(r'^admin/', admin.site.urls), ]
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
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)), ]
運用url()方法分發的示例:
urlpatterns = [ path('admin/', admin.site.urls), ... 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)) ]
擴展優化
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)), ]
"""MRBS URL Configuration The `urlpatterns` list routes URLs to views. For more information please see: https://docs.djangoproject.com/en/2.0/topics/http/urls/ Examples: Function views 1. Add an import: from my_app import views 2. Add a URL to urlpatterns: path('', views.home, name='home') Class-based views 1. Add an import: from other_app.views import Home 2. Add a URL to urlpatterns: path('', Home.as_view(), name='home') Including another URLconf 1. Import the include() function: from django.urls import include, path 2. Add a URL to urlpatterns: path('blog/', include('blog.urls')) """ from django.contrib import admin from django.urls import path from app01 import views from django.conf.urls import url 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, 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) # 鍵值就是全部的註冊表 for model, admin_class in admin.site._registry.items(): print("model", model) print("admin_class", admin_class) # app01.BookConfig """ 全部的註冊模型表 model <class 'django.contrib.auth.models.Group'> model <class 'app01.models.Book'> model <class 'app01.models.UserInfo'> model <class 'app01.models.Room'> """ # temp.append(path(r"app01/book", yuan)) # temp.append(path(r"%s/%s" % (app名稱怎麼取?, 模型名稱怎麼取?), yuan)) # 如何經過model類變量獲取該模型的字符串名稱和該模型所在的app的字符串名稱? # print("====>>", model._meta.model_name) # 模型名稱 book/userinfo/room # print("====>>", model._meta.app_label) # app名稱 app01 model_name = model._meta.model_name app_label = model._meta.app_label temp.append(path(r"%s/%s/" % (app_label, model_name), (get_urls2(), None, None))) return temp urlpatterns = [ path('admin/', admin.site.urls), path('login/', views.login), path('index/', views.index), path('book/', views.book), path('yuan/', (get_urls(), None, None)), ]
注意:
_registry:
{<class 'django.contrib.auth.models.Group'>: <django.contrib.auth.admin.GroupAdmin object at 0x105d24f98>,
<class 'app01.models.Book'>: <app01.admin.BookConfig object at 0x105d6d470>,
<class 'app01.models.UserInfo'>: <django.contrib.admin.options.ModelAdmin object at 0x105d6d5c0>,
<class 'app01.models.Room'>: <django.contrib.admin.options.ModelAdmin object at 0x105d6d5f8>}
def get_urls(): temp = [] print('_registry:', admin.site._registry) # 鍵值就是全部的註冊表 for model, admin_class in admin.site._registry.items(): print("model", model) # print("admin_class", admin_class) # app01.BookConfig """ 全部的註冊模型表 model <class 'django.contrib.auth.models.Group'> model <class 'app01.models.Book'> model <class 'app01.models.UserInfo'> model <class 'app01.models.Room'> """
def get_urls(): temp = [] for model, admin_class in admin.site._registry.items(): # temp.append(path(r"app01/book", yuan)) # temp.append(path(r"%s/%s/" % (app名稱怎麼取?, 模型名稱怎麼取?), yuan)) # 如何經過model類變量獲取該模型的字符串名稱和該模型所在的app的字符串名稱? print("====>>", model._meta.model_name) # 模型名稱 book/userinfo/room print("====>>", model._meta.app_label) # app名稱 app01
根據url多級分發規則:url(r"^yuan/"([url(r'^app01/book/',([url(r'12/delete/')],None,None)), ],None,None))
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 = [] for model, admin_class in admin.site._registry.items(): model_name = model._meta.model_name app_label = model._meta.app_label temp.append(path(r"%s/%s/" % (app_label, model_name), (get_urls2(), None, None))) return temp urlpatterns = [ path('admin/', admin.site.urls), path('yuan/', (get_urls(), None, None)), ]
顯示效果: