Question

This was posted to me

<*@google.com> wrote:

Hi Niklas,
If you just want to map this: /region/city/category/ supposing
its only
this valid characters: [a-zA-Z0-9_]
you can do the following:
– main.py

application =
webapp.WSGIApplication([(‘/([-\w]+)/([-\w]+)/([-\w]+)’,
handler)],debug=True)

and on your handler:
class Handler(webapp.RequestHandler):
def get(self, region, city, category):
# Use those variables on the method
Hope this helps!

My webapp is suppossed to handle URI like <region>/<city>/<category> with optional city and category e.g.

/rio_de_janeiro/grande_rio_de_janeiro/casas? #<region>/<city>/<category>
/gujarat/ahmedabad/vehicles-for_sale #<region>/<city>/<category>
/rio_de_janeiro/grande_rio_de_janeiro/ #<region>/<city>
/delhi #<region>

Etc Now I want to enable a request handler that can take optional arguments divided by the separator /. If I use the regex '/(.*) and variables in the request handler the first varible becomes a/b and the second variable becomes b so that is nearly what I want but a and b as 2 different variables instead. The regex I tried for the request handler is

application = webapp.WSGIApplication([('/(.*)',MyPage),

And the function head of my request handler is

class MyPage(RequestHandler):
    def get(self, location='frankfurt', category='electronics'):

To enable an HTTP query e.g. /frankfurt, /frankfurt/, /frankfurt/electronics, /madrid/apartments, /newyork, etc allowing all possible combinations. Can you advice me a regex that can achieve what I want? I want functionality like a mod_rewrite but for GAE.

Thanks

Clarification

It’s just a question of “make the directory a variable” so to clarify here are some examples how it should behave

‘/frankfurt’, – put ‘frankfurt’ in variable 1
‘/frankfurt/’, – put ‘frankfurt’ in variable 1
‘/frankfurt/electronics’, – put ‘frankfurt’ in variable 1 and ‘electronics’ in virable 2
‘/frankfurt/electronics/’, same as above
‘/eu/frankfurt/electronics’, same as above i.e. only last 2 groups count
‘/eu/frankfurt/electronics/’, same as above
‘toronto/lightnings’, doesn’t start with / so shan’t work
‘toronto/lightnings/’, as above
‘lima/cars/old’, as above
‘lima/cars/old/’ as above

Typical cases I want to handle is /region/city/category i.e. if I apply the example to Brazil it could be /rio_de_janeiro/grande_rio_de_janeiro/casas? for /region/city/category or for India it could be /delhi/delhi/for_sale or /gujarat/ahmedabad/vehicles-for_sale

Solution

As far as I can tell the solution from the answer works for my purposes:

/(?:[^/]+)/?([^/]*)/?([^/]*)

Answer 1

You can try

/(?:[^/]+)/?([^/]*)/?([^/]*)

which will put ‘a/b’ in variable 1, ‘a’ in variable 2 and ‘b’ in variable 3. Not sure if that is what you want.