如何循环遍历 django 中的对象字段

Question

我想遍历对象字段以更新它们的值，但我不太确定如何执行此操作。

class FinancePending(models.Model):
invoiceNumber = models.IntegerField
amountPaid = models.CharField(max_length=20)
AmountPending = models.IntegerField( blank=True, null=True)
TotalAmount = models.CharField(max_length=50, default=0)

现在我想计算一个函数中的金额。但它不起作用

     amount_paid = FinancePending.objects.values_list('amountPaid', flat=True)
        amount_paid = list(amount_paid)
        total_amount = FinancePending.objects.values_list('TotalAmount', flat=True)
        total_amount = list(total_amount)

        # total - paid
        TotalFee = [float(s.replace(',', '')) for s in total_amount]
        AmountPaid = [float(s.replace(',', '')) for s in amount_paid]
        finance_pending = FinancePending.objects.all()
        i = 0
        while i < len(TotalFee):
            amount_pending = TotalFee[i] - AmountPaid[i]
            FinancePending.objects.filter(invoiceNumber=i).values(AmountPending=amount_pending)
            setattr(finance_pending, 'AmountPending', str(amount_pending))
            i = 1 + i

Answer 1

建议使用Query Expression，更强大更健壮