How to manually authenticate user in Django

hi I want to authenticate user manually how can I keep user signed in, in all applications of project? here's my login view function:

def sign(request):
    context = {}
    if request.method == 'POST':
        form = SigninForm(data = request.POST)
        if form.is_valid:
            username = request.POST['username']
            password = hashlib.sha256(request.POST['password'].encode('utf-8')).hexdigest()
            users = customer.objects.all()          
            for user in users:
                if username == user.username:
                    if password == user.password:
                        context['tmp'] = "OK"