When I run into this issue, I use AJAX to make 2 dependents choices. First I use Django Form , for example:

# I avoid the importation of the choices to make answer shorter
class YourForm(forms.Form):    
    industry = forms.ChoiceField(choices=USER_PROFILE_CURRENT_INDUSTRY_TYPES)
    sector = forms.ChoiceField(choices=USER_PROFILE_CURRENT_SECTOR_TYPES)    
    # ... other fields

      

        
        
        
      

    

I will avoid the basics of submission (how to manage GET / POST methods) and the basic django HTML form, I will go directly to the AJAX function :

Suppose the selector IDs are: and #id_sector

#id_industry

function get_industry(){
            jQuery.ajax({
              async: false,
              type: "POST",
              url: "/a/get/industry/",
              data: "sector_id=" + $('#id_sector').val(),
              success: function(response) {
                    result = JSON.parse(response);
                    if (result) {
                        // I usually receive a list of items here
                        // I use this list to replace the dependant select                                                

                        $('#id_industry').empty()  // Use to empty the select

                        // Now we append the industry options we've received
                        for(var i=0;i < result.item_list.length;i++){
                            $('#id_industry').append($('<option>', { 
                                value: result.item_list[i]['id'],
                                text: result.item_list[i]['name'] 
                        }));      
                        }

                    } else {
                        console.log('error');
                    }
                }
            });
        }

function get_sector(){
            jQuery.ajax({
              async: false,
              type: "POST",
              url: "/a/get/sector/",
              data: "industry_id=" + $('#id_industry').val(),
              success: function(response) {
                    result = JSON.parse(response);
                    if (result) {
                        $('#id_sector').empty()  // Use to empty the select

                        // Now we append the sector options we've received
                        for(var i=0;i < result.item_list.length;i++){
                            $('#id_sector').append($('<option>', { 
                                value: result.item_list[i]['id'],
                                text: result.item_list[i]['name'] 
                        }));                                                   
                        }

                    } else {
                        console.log('error');
                    }
                }
            });
        }

      

        
        
        
      

    

Now I'm going to show the AJAX view . You can customize the AJAX view in a file called ajax.py:

from yourapp.models import USER_PROFILE_CURRENT_SECTOR_TYPES

INDUSTRY_DICT = {
    4: range(14,36),
    5: range(36,58),
    6: range(58,80),
    7: range(80,102),
    8: range(102,124),
    10: range(124,146)  # This is the only true equivalence that you passed to me
}

@csrf_exempt
def get_sectors(request):
    response = []
    industry_id = int(request.POST['industry_id'])

    # With the sector_id you know wich sector the user has selected
    # You should generate the list based in your needs
    data = []
    if industry_id:
        sectors = INDUSTRY_DICT[industry_id]  # This return a list of ID of sectors
        # Then make loop over all sectors
        for sector_id in sectors:  
            # To get the sector name you should use another dict
            # I think you already have it in USER_PROFILE_CURRENT_SECTOR_TYPES
            # Remember to import it (check above)
            sector_name =  USER_PROFILE_CURRENT_SECTOR_TYPES[sector_id]
            # We append the id and the name to replace options in the HTML
            data.append({'id':sector_id, 'name':sector_name})  

        response = { 'item_list':data }  # We send back the list
        return HttpResponse(simplejson.dumps(response))

    # If we get any error, or cannot get the sector, we send an empty response
    response = {}
    return HttpResponse(simplejson.dumps(response))

      

        
        
        
      

    

I will not add the second AJAX function get_sectors

'because I suppose you understand the logic, it should be the same as this function, but you get industry_id

instead sector_id

, I think you might run into the second function.

The final step before setting up URLs is defining functions that control changes to the selection and calling of AJAX functions:

    $("#id_sector").change(function(){           
            get_industry();  // AJAX function call when sector is selected           
    });

    $("#id_industry").change(function(){           
            get_sector();  // AJAX function call when industry is selected             
    });

      

        
        
        
      

    

You need to add both urls to urls.py :

# ... YOUR OTHER URLS
url(r'^a/get/industry/?$', 'yourproject.ajax.get_industries', name='get_industries'),
url(r'^a/get/sector/?$', 'yourproject.ajax.get_sectors', name='get_sectors'),

      

        
        
        
      

    

Tips:

• When you see $('#id_industry')
  
  it refers to the industry selector ID, just like it $('#id_sector')
  
  refers to the sector selector ID

• What I call AJAX function comes in HTML template

• What I call AJAX view goes into the file .py
  
  , I usually add AJAX views to the fileajax.py
  
  
• In this example, I added an AJAX@csrf_exempt
  
  to the view . If you want to know how to manage CSRF token in AJAX , you can go to: CSRF and AJAX: official docs
• In the AJAX view , you have the Sector that the user selected:
  • You need to create a list of industries
  • The list will be used to create the select parameters
  • You can do this in different ways, you should choose the one that best suits your scenario.
  • I am posting the ID, but you can post the name if it is better for you.

Edit: filter sector / industry

• get_industries(request)
  
  changed to get_sectors(request)
  
  

First of all you must have equivalents, you can have them in different ways, you can have 2 industry and sector models and link them with foreign keys, but I think you don’t have models so you can have 2 dictionaries one for industries and one for sector.

I'll judge the equivalence, you should change the dict values ​​to the ones you need:

INDUSTRY_DICT = {
4: range(14,36),
5: range(36,58),
6: range(58,80),
7: range(80,102),
8: range(102,124),
10: range(124,146)  # This is the only equivalence that you passed to me
}

      

        
        
        
      

    

This will create a dict and if you do INDUSTRY_DICT[industry_id]

it will return a list of sector ids that should appear in the select. Check out the above function with new changes.

• I also recommend you 2 more functions to "restart" both options and add all possible options again if the user wants to change their choice.