with and without DI

with_di.py

def complete_purchase(request, user_db: UserDb, payment_service: Payments, basket: BasketApi):
    some_validation(request)
    customer = user_db.get_customer(request.user.id)
    customer.check_credit_history()
    try:
      payment = payment_service.complete_payment(request.payment_token)
      customer.add_to_payment_history(payment)
      basket.close_basket(request.basket_id)
      return Response({"okey": "dokey"})
    except:
      return Response({"fail": "bad"})
    

add_to_app_route(POST, "/purchase/", bind_dependencies_somehow(complete_purchase))

without_di.py

def complete_purchase(request):
    some_validation(request)
    customer = user_db.get_customer(request.user.id)
    customer.check_credit_history()
    try:
      payment = payment_service.complete_payment(request.payment_token)
      customer.add_to_payment_history(payment)
      basket.close_basket(request.basket_id)
      return Response({"okey": "dokey"})
    except:
      return Response({"fail": "bad"})
    
    
add_to_app_route(POST, "/purchase/", complete_purchase)