Access to Request.user from the Django model

I am writing a site on Django. There is such a problem: there is a Client model for almost everywhere on the site the user must display his customers. At first, I wrote in every form like this:

  client.objects.  Filter  (User = Request.user)     
 Then I made his manager with the method to which you need to transmit the user, but in general it does not relieve the problem to constantly transfer the user. How can you make a current user available in Models.py?