Code sample of Python/Django

django_example.py

class ApplyCredit(APIView):
    permission_classes = [IsAuthenticated]

    def post(self, request):
        """
        Apply credit on bill.com
        """
        try:
            audit_log = AuditLog(user=request.user)
            billee_id = request.POST.get('billee_id')
            if not billee_id or billee_id == 'undefined':
                return CustomResponse(message="Please select Billee").error()
            
            if not Billee.objects.filter(id=billee_id).exists():
                return CustomResponse(message="Invalid Billee").error()
            
            billee_credit = True
            credit_amount = request.POST.get('credit_amount')
            if not credit_amount:
                return CustomResponse(message="Please enter credit amount").error()
            amount_reason = request.POST.get('amount_reason')
            
            if not amount_reason:
                return CustomResponse(message="Please enter amount reason").error()
	     
	          credit_amount = round(float(credit_amount), 2)
            #Create customer and invoice in bill.com
            flag = apply_credits_to_customers(billee.id, credit_amount, False, None)
            # if invoice credit is already applied against billee add new amount to credit amount.
            
            if flag:
                if billee.invoice_credit:
                    invoice_credit = billee.invoice_credit
                    prev_obj = copy.copy(invoice_credit)
                    invoice_credit.credit_amount = credit_amount + float(invoice_credit.credit_amount)
                    invoice_credit.amount_reason = invoice_credit.amount_reason + ', ' + amount_reason
                    invoice_credit.save()
                    
                    # make an entry in audit log
                    audit_log.edit(prev_obj=prev_obj, new_obj=invoice_credit)
                else:
                    # else create new InvoiceCredit obj and add the credit amount
                    invoice_credit = InvoiceCredit.objects.create(credit_amount=credit_amount, amount_reason=amount_reason)
                    billee.invoice_credit = invoice_credit
                    billee.save()
                    
                    # make an entry in audit log
                    audit_log.create(instance=billee.invoice_credit, extra_str=", General credit applied")
                
                return CustomResponse(message="Credit Applied Successfully!").response()
            
            else:
                return CustomResponse(
                    message="Billee doesn't exist on Bill.com or there maybe some technical issue").error()
        except:
            traceback.print_exc()
            return CustomResponse(message=SOMETHING_WENT_WRONG).error()
    
    def get(self, request):
        return CustomResponse(message=INVALID_METHOD).error()