please help me in finding solution 

 i have two drop down  in Xml template  (using only controller not model.py )

Note : i am getting countries and states as follows using controller 

country = request.env['res.country'].search([])

state = request.env['res.country.state'].search([])

in first drop down when i  select country  india

then i want to see on states related with india in second drop down field

Thanks in advance