程序设计基础django book20中文版

URLURLconfURLconfDjangoPython流线型化(Streamlining)看下这个URLconf，fromdjango.conf.urls.defaultsimportfromdjango.conf.urls.defaultsimportfrommysite.views o,current_datetime,urlpatterns=patterns('', (r'^time/$',current_datetime),(r'^time/plus/(\d{1,2})/$',hours_ahead),)正如第三章中所解释的，在URLconf中的每一个但随着Django应用变得复杂，它的URLconf也在增长，并且这些导入可viewsURLconffromdjango.conf.urls.defaultsimportfromdjango.conf.urls.defaultsimport**frommysiteimporturlpatterns= o/$',**views. o**),(r'^time/$',**views.current_datetime**),(r'^time/plus/(d{1,2})/$',**views.hours_ahead**)Django还提供了 法可以在URLconf中为某个特别的模式指定视图fromdjango.conf.urls.defaultsimportfromdjango.conf.urls.defaultsimporturlpatterns= o/$',**'mysite.views. o'**),(r'^time/$',**'mysite.views.current_datetime'**),(r'^time/plus/(d{1,2})/$',**'mysite.views.hours_ahead'**)'mysite.views.current_datetime'mysite.views.current_datetime使用这个技术，就不必导入视图函数了；Django``\们可以把公共的前缀提取出来，作为第一个参数传给\``函数：SystemMessage:WARNING/2(<string>,line99);Inlinelilstart-stringwithoutend-fromdjango.conf.urls.defaultsimportfromdjango.conf.urls.defaultsimporturlpatterns=patterns(**'mysite.views'**, o/$',**' o'**),(r'^time/$',**'current_datetime'**),(r'^time/plus/(d{1,2})/$',**'hours_ahead'**)注意既不 号。Django如果你的视图函数存在于几个不同的Python模块的话，它可以使得更容易对视图函数进行包装(wrap)更Pythonic，就是说，更符合Python的传统，如把函数当成对象传递。URLconfURLconf少重复。只要增加多个patterns()对象，象这样:fromdjango.conf.urls.defaultsimportfromdjango.conf.urls.defaultsimporturlpatterns= o/$','mysite.views. (r'^time/$','mysite.views.current_datetime'),(r'^time/plus/(\d{1,2})/$','mysite.views.hours_ahead'),(r'^tag/(\w+)/$','weblog.views.tag'),)urlpatternsurlpatterns=patterns('mysite.views', o/$',' (r'^time/$','current_datetime'),(r'^time/plus/(\d{1,2})/$',)urlpatterns+=patterns('weblog.views',(r'^tag/(\w+)/$','tag'),)整个框架关注的是存在一个名为urlpatterns，patterns()返回的对象是可URLconfDEBUGfromdjango.confimportfromdjango.confimportfromdjango.conf.urls.defaultsimport*frommysiteimportviewsurlpatterns=patterns('',(r'^$',views.homepage),(r'^(\d{4})/([a-z]{3})/$',)ifurlpatterns+=patterns('',(r'^debuginfo/$',views.debug),)在这个例子中，URL/debuginfo/只在你的DEBUG配置为True时URLconfURL，Django会将捕获的文本作为位置参数传递给视图函数。在更高级的用法中，还可以使用命名正则表达式组来捕URL，并且将其作为关键字参数传给视图。defsell(item,defsell(item,print"Selling%sunit(s)of%sat%s"%ty,item,sell('Socks','$2.50',sell('Socks','$2.50',sell(item='Socks',sell(item='Socks',sell(item='Socks',ty=6,sell(price='$2.50',item='Socks',ty=6)sell(price='$2.50',ty=6,item='Socks')sell(ty=6,item='Socks',price='$2.50')sell(ty=6,price='$2.50',sell('Socks','$2.50', sell('Socks','$2.50', sell('Socks',price='$2.50', ty=6,在Python(?P<name>pattern)namepattern下面是一个使用无名组的URLconf的例子:fromfromdjango.conf.urls.defaultsimport*frommysiteimportviewsurlpatterns=patterns('',(r'^articles/(\d{4})/$',views.year_archive),(r'^articles/(\d{4})/(\d{2})/$',)下面是相同的URLconf，fromfromdjango.conf.urls.defaultsimport*frommysiteimportviewsurlpatterns=patterns('',(r'^articles/(?P<year>\d{4})/$',views.year_archive),)/articles/2006/03/month_archive(request,'2006',month_archive(request,'2006',month_archive(request,year='2006',month_archive(request,year='2006',URLconfsBUG，URL前面，而不使用命名组的话，我们就不得不去修改视当然，命名组的代价就是失去了简洁性：一些开发者觉得命名组的语法和显得冗余。命名组的另一个好处就是可读性强。URLconfURLURLconf否则，Django##fromdjango.conf.urls.defaultsimport*frommysiteimportviewsurlpatterns=patterns('',(r'^foo/$',views.foo_view),(r'^bar/$',)#fromdjango.shortcutsimportrender_to_responsefrommysite.modelsimportMyModeldefm_list=return te1.html',{'m_list':defdefm_list=return te2.html',{'m_list':##fromdjango.conf.urls.defaultsimport*frommysiteimportviewsurlpatterns=patterns('',(r'^(foo)/$',views.foobar_view),(r'^(bar)/$',)#fromdjango.shortcutsimportrender_to_responsefrommysite.modelsimportMyModeldeffoobar_view(request,m_list=MyModel.objects.filter(is_new=True)ifurl=='foo': te_name='tem elifurl=='bar': te_name= return te_name,{'m_list':这种解决方案的问题还是老缺点，就 的URL耦合进你的代码里面了。/foo//fooey/URLURLconf包含第三个数据：一个关键字参数的字典：##fromdjango.conf.urls.defaultsimport*frommysiteimportviewsurlpatterns=(r'^foo/$',views.foobar_view,{'tem (r'^bar/$',views.foobar_view,{'tem (r'^bar/$',views.foobar_view,{'tem )#fromdjango.shortcutsimportrender_to_responsefrommysite.modelsimportMyModeldeffoobar_view(request, m_list=return te_name,{'m_list':如你所见，这个例子中，URLconf指定了temte_name。而视图函数会把URLconf额外信息的一个好方法。正因如此，这技术已被很多Django的应用使用，其中以在第11章讨论的通用视图系统最为明显。URLURLconfURL例如，你可能有一个显示某一个特定日子的某些数据的应用，URL#...URLconf（使用命名组的方法urlpatterns=patterns('',(r'^mydata/(?P<month>\w{3})/(?P<day>\d\d)/$',urlpatterns=patterns('',(r'^mydata/(?P<month>\w{3})/(?P<day>\d\d)/$',views.my_view),)defdefmy_view(request,month,day):#用my_viewmonthdayURLURL，/mydata/birthday/URL/mydata/jan/06/URLconfurlpatterns=urlpatterns=(r'^mydata/birthday/$',views.my_view,{'month':'jan','day':(r'^mydata/(?P<month>\w{3})/(?P<day>\d\d)/$',)monthdayPythondefprinto,%s'defsay_goodbye(print'Goodbye,%s'%defdef_name,print'%s,%s'% URLconfDjango示一系列的Event对象，那个视图显示一系列的BlogEntry对象，并它##fromdjango.conf.urls.defaultsimport*frommysiteimportviewsurlpatterns=patterns('',(r'^events/$',views.event_list),(r'^blog/entries/$',)#fromdjango.shortcutsimportrender_to_responsefrommysite.modelsimportEvent,BlogEntrydefdefobj_list=defobj_list=return{'entry_list':##fromdjango.conf.urls.defaultsimport*frommysiteimportmodels,viewsurlpatterns=(r'^events/$',views.object_list,{'model':models.Event}),(r'^blog/entries/$',views.object_list,{'model':)#fromdjango.shortcutsimportrender_to_responsedefobject_list(request,model):obj_list= te_name='mysite/%s_list.html'%model.name.lower()returnrender_to_response(tem te_name,{'object_list':modelURLconfmodel.objects.all()（我们使用model.name.lower()Python一个name的这种情况下很有用。比如，BlogEntry'BlogEntry'

nameblogentry_listevent_list因为数据库驱动的都有一些通用的模式，Django提供了一个通用视图的集合使用它可以节省你的时间。会在下一章讲讲Django的内置通用视图。URLconfdefmy_view(request,tem defmy_view(request,tem var=do_something()return te_name,{'var':当出现的时候额外URLconf参数优先于捕捉值。也就是说如果URLconfURLconfURLconffromfromdjango.conf.urls.defaultsimport*frommysiteimportviewsurlpatterns=(r'^mydata/(?P<id>\d+)/$',views.my_view,{'id':)id（额外字典的）id（/mydata/2//mydata/432432/）都会作id设置为3URLid##fromdjango.conf.urls.defaultsimport*frommysiteimportviewsurlpatterns=patterns('',(r'^blog/$',views.page),(r'^blog/page(?P<num>\d+)/$',))#defpage(request,#Outputtheappropriatepageofblogentries,accordingtonum.#...page()num"1"page()num（``‘1’````1``为了保持一致，因为捕捉给``num``的值总是字符串。defmy_view(request,tem defmy_view(request,tem var=do_something()return te_name,{'var':URLURLconf位的线性处理方式。urlpatternsurlpatterns=patterns('',#...('^([^/]+)/([^/]+)/add/$',views.add_stage),#...)这将匹配像/myblog/entries/add/和/auth/groups/add/URL显示所有的表单域，它显示两个域等等。我们可以在视图中特别以defadd_stage(request,app_label,defadd_stage(request,app_label,ifapp_label=='auth'andmodel_name=='user':#dospecial-casecode#donormalURLURLconfurlpatternsurlpatterns=patterns('',#...('^auth/user/add/$',views.user_add_stage),('^([^/]+)/([^/]+)/add/$',views.add_stage),#...)/auth/user/add/的请求将会被user_add_stageURL（）URL每个获的参数将被作为纯Python字符串来发送，而不管正则表达式中的格URLConf(r'^articles/(?P<year>\d{4})/$',(r'^articles/(?P<year>\d{4})/$',尽管\d{4}将只匹配整数的字符串，但是参数yearviews.year_archive()Python类型的对象。一个典型的的错误就是用字符串值而不是整数值来创建datetime.date对象：>>>import>>>import>>>datetime.date('1993','7','9')Traceback(mostrecentcalllast):TypeError:anintegeris>>>datetime.date(1993,7,datetime.date(1993,7,URLconf##fromdjango.conf.urls.defaultsimport*frommysiteimportviewsurlpatterns=patterns('',(r'^articles/(\d{4})/(\d{2})/(\d{2})/$',views.day_archive),)#views.pyimportdatetimedefday_archive(request,year,month,##ThefollowingstatementraisesaTypeError!date=datetime.date(year,month,day)因此，day_archive()defday_archive(request,year,month,defday_archive(request,year,month,date=datetime.date(int(year),int(month),注意，当你传递了一个并不完全包含数字的字符串时，int()URLconf参数或。它也不包括第一个斜杠，因为每个URL必定有一个斜杠。例如，在向http myapp/。在向http /myapp/?page=3的请求中，Django同样会去匹配myapp/。URLconf（POSTGETHEAD）被考虑这个URLconf/view设计:##fromdjango.conf.urls.defaultsimport*frommysiteimportviewsurlpatterns=patterns('',#...(r'^somepage/$',views.some_page),#...)#fromdjango.httpimportHttp404,HttpResponseRedirectfromdjango.shortcutsimportrender_to_responsedefifrequest.method=='POST':returnHttpResponseRedirect('/someurl/')elifrequest.method=='GET':returnrender_to_response('page.html')raise在这个示例中，``some_page()``视图函数对``POST``和``GET``求方法的处理完全不同。它们唯一的共同点是共个URL地址：个分开的视图函数——一个处理``POST````GET``帮我们改进前边那个简单的``some_page()``视图的：##fromdjango.httpimportHttp404,HttpResponseRedirectfromdjango.shortcutsimportrender_to_responsedefmethod_splitter(request,GET=None,POST=None):ifrequest.method=='GET'andGETisnotNone:returnelifrequest.method=='POST'andPOSTisnotNone:returnPOST(request)raisedefassertrequest.method=='GET'returndefassertrequest.method=='POST'returnHttpResponseRedirect('/someurl/')#urls.pyfromdjango.conf.urls.defaultsimport*frommysiteimportviewsurlpatterns=patterns('',#...(r'^somepage/$',views.method_splitter,views.some_page_get,views.some_page_get,'POST':views.some_page_post}),#...)``method_splitter()````request.method``返回的值来调用相应的视图。可以看到它带有两个关键参数，``GET``和``POST``**``request.method````GET``那它就会自动调用``GET``视图。如果``request.method``返回的是``POST``，那它调用的就是``POST``视图。如果``request.method``返回的是其它值（如：``HEAD``，或者是没有把``GET``或``POST``提交给此函数，那它就会抛出一个``Http404``错误。URLconf``/somepage/````method_splitter()``并把视图函数额外需要用到的``GET``和``POST``参数传递给它。最终，我们把``some_page()``视图分解到两个视图函数中``some_page_get()````some_page_post()``method_splitter()``（比如，``some_page_post()``调用的时候，我们可以确信``request.method````post``）当``request.method``defmethod_splitter(request,*args,**kwargs):get_view=kwargs.pop('GET',None)post_view=kwargs.pop('POST',None)ifrequest.method=='GET'andget_viewdefmethod_splitter(request,*args,**kwargs):get_view=kwargs.pop('GET',None)post_view=kwargs.pop('POST',None)ifrequest.method=='GET'andget_viewisnotNone:returnget_view(request,*args,**kwargs)elifrequest.method=='POST'andpost_viewisnotNone:returnpost_view(request,*args,**kwargs)raisemethod_splitter(),GETPOST持使用*args**kwargs(注意*Python参数前面加一个*号,所有传递给函数的参数将会保存为一个元组.如果你在函deffoo(*args,deffoo(*args,print"Positionalargumentsare:"printargsprint"Keywordargumentsare:"printkwargs>>>foo(1,2,>>>foo(1,2,Positionalarguments(1,2,Keywordarguments>>>foo(1,2,name=' ',framework='Django')Positionalargumentsare:(1,Keywordarguments{'framework':'Django','name': None,KeyError)python视图里重复了大量代码，就像这个例子：defdefifnotreturnHttpResponseRedirect('/accounts/login/')#...return defifnotreturnHttpResponseRedirect('/accounts/login/')#...return defifnotreturnHttpResponseRedirect('/accounts/login/')#...returnreturn request.user用户已经成功登陆站点否则就重定向/accounts/login/request.user,但是14章将要讲到它.就如你所想像的,request.user当前用户是登陆的还是)defdefdefnew_view(request,*args,ifnotreturnHttpResponseRedirect('/accounts/login/')returnview(request,*args,**kwargs)returnrequires_login,view,new_view.new_viewrequires_loginviewsifnotrequest.user.is_authenticated()URLconfrequires_loginfromdjango.conf.urls.defaultsimportfromdjango.conf.urls.defaultsimportfrommysite.viewsimportrequires_login,my_view1,my_view2,urlpatterns=(r'^view1/$',requires_login(my_view1)),(r'^view2/$',requires_login(my_view2)),(r'^view3/$',requires_login(my_view3)),)URLconfDjangoURLconf在任何时候，你的URLconf都可以包含其他URLconf模块。对于根 URLconffromdjango.conf.urls.defaultsimportfromdjango.conf.urls.defaultsimporturlpatterns=(r'^weblog/',include('mysite.blog.urls')),(r'^photos/',include('mysite.photos.urls')),(r'^about/$','mysite.views.about'),)URLconf,includeinclude()的正则表达式并不包含一个$（字符串结尾匹配符Djangoinclude()URLconfmysite.blog.urls：fromd