Django的URL路由系统

from django.conf.urls import url
#循环urlpatterns,找到对应的函数执行,匹配上一个路径就找到对应的函数执行,就不再往下循环了,并给函数床底一个参数request,和wsgiref的environ类似,就是请求信息的所有内容
urlpatterns = [
                url(正则表达式,views.函数,{"参数":别名}),
]        

from django.urls import path

urlpatterns = [
    path('articles/2003/', views.special_case_2003),
    path('articles/<int:year>/', views.year_archive),
    path('articles/<int:year>/<int:month>/', views.month_archive),
    path('articles/<int:year>/<int:month>/<slug:slug>/', views.article_detail),
]

from django .conf.urls import url

from app(应用) import views

urlpatterns = [

    url(r'^articles/2003/$', views.special_case_2003), #思考：
如果用户想看2004、2005、2006....等，你要写一堆的url吗，
是不是在articles后面写一个正则表达式/d{4}/就行啦，网址里面输入
127.0.0.1:8000/articles/1999/试一下看看
    url(r'^articles/([0-9]{4})/$', views.year_archive), 
    url(r'^articles/([0-9]{4})/([0-9]{2})/$', views.month_archive), #思考，
如果你想拿到用户输入的什么年份，并通过这个年份去数据库里面匹配对应年份的文章，你怎么办？
怎么获取用户输入的年份啊，分组/(\d{4})/，一个小括号搞定
    url(r'^articles/([0-9]{4})/([0-9]{2})/([0-9]+)/$', views.article_detail),
]

# 是否开启URL访问地址后面不为/跳转至带有/的路径的配置项
APPEND_SLASH=True

from django.conf.urls import url
from app01 import views

urlpatterns = [
        url(r'^blog/$', views.blog),

from django.conf.urls import url

from . import views

urlpatterns = [
    url(r'^articles/2003/$', views.special_case_2003),  #主意正则匹配出来的是字符串,
即便是你在url里边写的是2003数字,匹配出来的也是字符串.
    url(r'^articles/(\d{4})/$', views.year_archive),#year_archive(request,2003),
小括号表示分组,有分组,name这个分组得到的是用户输入的内容,就会作为对应函数的位置参数传进去,
别忘了形参要写两个.
    url(r'^articles/(?P<year>[0-9]{4})/$', views.year_archive),#某年的，
(?P<year>[0-9]{4}),这是命名参数(正则命名匹配),那么函数year_archive(request,year),
形参名称必须是year这个名字.而且注意如果你这个正则后面没有$符号,即便是输入了月份路径,
也会被它拦截下来,因为它的正则也能匹配上
    url(r'^articles/(?P<year>[0-9]{4})/(?P<month>[0-9]{2})/$', views.month_archive),
#某年某月的
    url(r'^articles/(?P<year>[0-9]{4})/(?P<month>[0-9]{2})/(?P<day>[0-9]{2})/$', 
views.article_detail), #某年某月某日的
]

views.month_archive(request, year="2017", month="12")，year和month的位置可以换，
没所谓了，因为是按照名字来取数据的.

url(r'^articles/(?P<year>[0-9]{4})/$', views.year_archive),

# urls.py中
from django.conf.urls import url

from . import views

urlpatterns = [
    url(r'^blog/$', views.page),
    url(r'^blog/page(?P<num>[0-9]+)/$', views.page),
]

# views.py中，可以为num指定默认值
def page(request, num="1"):
    pass

urlpatterns = [
   url(r'^admin/', admin.site.urls),
   url(r'^blog/', include('blog.urls')),  # 可以包含其他的URLconfs文件
   url(r'^app01/',include('app01.urls')),#别忘了要去app01这个应用下创建一个urls.py
的文件,现在的意思是凡是以app01开头的路径请求,都让它去找app01下面的urls文件中去找对应的视图函数
,还要注意一点,此时的这个文件里面的那个app01路径不能用$结尾,因为如果写了$,
就没办法匹配app01/后面的路径了.

from django.conf.urls import url
#from django.contrib import admin
from app01 import views

urlpatterns = [
    # url(r'^admin/', admin.site.urls),
    url(r'^articles/2003/', views.special_case_2003,{'foo':'xxxxx'}),
    url(r'^articles/(\d{4})/(\d{2})/', views.year_archive),

]

url(r'^$',views.index),#以空开头,还要以空结尾,写在项目的urls.py文件里面就是项目的首页,写在应用文件夹里面的urls.py文件中,那就是app01的首页.

url(r'^home', views.home, name='home'),  #给我的url匹配模式起名(别名)为home,别名不需要改,
路径你就可以随便改了,别的地方使用这个路径,就用别名来搞.
url(r'^index/(\d*)', views.index, name='index'),  # 给我的url匹配模式起名为index

{% url 'home' %}  #模板选择的时候,被django解析成了这个名字对应的url,这个过程叫做反向解析

from django.urls import reverse

reverse("index", args=("2018", ))

from django.conf.urls import url

from . import views

urlpatterns = [
    # ...
    url(r'^articles/([0-9]{4})/$', views.year_archive, name='news-year-archive'),
    # ...
]

<a href="{% url 'news-year-archive' 2012 %}">2012 Archive</a>

<ul>
{% for yearvar in year_list %}
<li>
<a href="{% url 'news-year-archive' yearvar %}">{{ yearvar }}Archive</a>
</li>
</ul>

from django.urls import reverse
from django.shortcuts import redirect

def redirect_to_year(request):
    # ...
    year = 2006
    # ...
    return redirect(reverse('news-year-archive', args=(year,)))