Django URL正则表达式“不是有效的正则表达式”错误

Question

I'm having a bit of trouble configuring the following url. I want it to be able to match a pages which start off with a category and then finish with a slug, examples:

/category1/post1/
/category2/post2/
/category3/post3/
/category1/post4/
/category2/post5/

I've tried many different methods with no success... I always get an "is not a valid regular expression" error. This is how I thought it should work:

url(r'^(?P<category1|category2|category3>[\w\-]+)/(?P<slug>[\w\-]+)/$', blog_post, name = 'blog_post'),

I am fairly new to regex and trying to learn so any help on this one with an explanation would be much appreciated :)

Answer 1

Your pattern is incorrect; you are putting the alternative values in the wrong place. You put them in the name of the group:

(?P<category1|category2|category3>...)

Put them in the part the name is supposed to match instead:

(?P<category>category1|category2|category3)

Making the full registration:

url(r'^(?P<category>category1|category2|category3)/(?P<slug>[\w\-]+)/$', blog_post, name='blog_post'),

I'm assuming your blog_post callable looks something like:

def blog_post(category, slug):