How to handle user mangement in Django for groups that has same access but different rules?
If I'm understanding you correctly, it seems like you want to have two different groups have access to all the same views, but they will see different numbers. You can achieve this effect by making separate templates for the different groups, and then loading the appropriate template for each view depending on the group of the current user.
Similarly you can use a context processor to put the current group into the context for every view, and then put conditionals in the templates to select which numbers to show.
The other option is to have two separate sets of views for the two different groups. Then use decorators on the views to make sure the groups only go to the views that are for them.
Background information:
I have created an internal site for a company. Most of the work has gone into making calculation tools that their sale persons can use to make offers for clients. Create pdf offers and contracts that can be downloaded, compare prices etc. All of this is working fine.
Now their sale persons have been divided into two groups.

One group is sale personal that is hired by the company.
The other group is persons a company themselves.

The question:
My challenge now is, that I in some cases need to display different things depending on the type of sales person. Some of the rules for the calculation tools will have different rules as to which numbers will be allowed etc. But a big part of the site will still be the same for both groups.
What I would like to know, is if there is a good way of handling this problem?
My own thoughts:
I thought about managing this by using the groups that is available in contrib.auth. That way I could keep a single code base, but would have to make rules a lot of different places. Rules for validating forms to check if the numbers entered is allowed, will depend on the group the user is in. Some things will have different names, or the workflow might be a bit different. Some tools will only be available to one of the groups. This seems like a quick solution here and now, but if the two groups will need to change more and more, it seems like this would quickly become hard to manage.
I also thought about making two different sites. The idea here was to create apps that both groups use, so I only would need to make the code for that 1 place. Then I could make the custom parts for each site and wouldn't need to check for the user in most templates and views. But I'm not sure if this is a good way to go about things. It will create a lot of extra work, and if the two groups can use a lot of the same code, this might not really be needed.
The biggest concern is that I don't really know how this evolve, so it could end up with the two groups being entire different or with only very few differences. What I would like to do, is write some code that can support both scenarios so I wont end up regretting my choice a half year from now.
So, how do you handle this case of user management. I'm looking for ideas techniques or reusable apps that address this problem, not a ready made solution.
Clarifications:
My issue is not pure presentation that can be done with templates, but also that certain calculation tools (a form that is filled out) will have different rules/validation applied to them, and in some cases the calculations done will also be different. So they might see the same form, but wont be allowed to enter the same numbers, and the same numbers might not give the same result.