如下是django框架中urls.py的代码，urlpatterns为什么要分开写，那个空字符串又是做什么的呢？

Question

代码如下：
1#coding:utf8
2
3fromdjango.conf.urls.defaultsimportpatterns,url
4
5fromviews.informationimportinformation
6fromviews.long_relatedimportlong_related
7fromviews.relatedimportrelated
8
9urlpatterns=[]
10urlpatterns+=patterns(
11'',#这个空字符串的作用是什么？
12url(r'^video/app/article/information/$',information,{'version':17}),
13url(r'^video/app/article/information/v(?P\d+)/$',information),
14url(r'^test/information/v(?P\d+)/$',information),
15)
16
17urlpatterns+=patterns(#为什么要另外定义一个patterns加到urlpatterns中？
18'',
19url(r'^video/app/article/related/$',related,{'version':1}),
20url(r'^video/app/article/related/v(?P\d+)/$',related),
21)
22
23urlpatterns+=patterns(
24'',
25url(r'^video/app/article/related/long/$',long_related,{'version':1}),
26)
问题也如代码中的注释，首先为什么要append三个patterns，合在一起不行吗？比如
9urlpatterns=[]
10urlpatterns+=patterns(
11'',#这个空字符串的作用是什么？
12url(r'^video/app/article/information/$',information,{'version':17}),
13url(r'^video/app/article/information/v(?P\d+)/$',information),
14url(r'^test/information/v(?P\d+)/$',information),
19url(r'^video/app/article/related/$',related,{'version':1}),
20url(r'^video/app/article/related/v(?P\d+)/$',related),
25url(r'^video/app/article/related/long/$',long_related,{'version':1}),
26)
另外，patterns里面有一个空字符串‘’，这是干什么的呢？

Answer 1

1、为什么要append三个pattern为了可读性和可维护性，通常会把相同功能或相似url的放到一组里面这是不同人的不同写法，当然可以所有的都写到一起2、patterns里面有一个空字符串‘’，这是干什么的呢patterns(prefix,*args)方法的第一个参数