我如何在 django 中执行数学运算？答案

【问题标题】：how do i perform a math operation in django?我如何在 django 中执行数学运算？
【发布时间】：2022-08-15 17:29:10
【问题描述】：

当用户从他们的main balance 提取任何金额时，我正在尝试计算new_balance。

我正在尝试在提交表单时执行此操作，但我不知道这是否是执行此操作的完美方式。这就是我想要达到的目标。

def withdrawal_request(request):
    ...
    if request.method == \"POST\":
        form = WithWithdrawalRequestForm(request.POST)
        if form.is_valid():
            new_form = form.save(commit=False)
            new_form.user = request.user

            if new_form.amount > all_earning:
                messages.warning(request, \"You cannot withdraw more than what is in your wallet balance.\")
                return redirect(\"core:withdrawal-request\")
            elif pending_payout > new_balance:
                messages.warning(request, \"You have reached your wallet limit\")
                return redirect(\"core:withdrawal-request\")
            else:
                new_form.save()
                new_balance = new_balance - new_form.amount
                messages.success(request, f\"Withdrawal Request Is Been Processed...\")
                return redirect(\"core:withdrawal-request\")
        
    else:
        form = WithWithdrawalRequestForm(request.POST)
        

    context = {
            \"form\":form,
            \"new_balance\":new_balance,
        }
    return render(request, \"core/withdrawal-request.html\", context)

标签： python django django-rest-framework django-views

【解决方案1】：

我实际上又少了一行

else:
   new_form.save()
   request.user.profile.main_all_earning = main_all_earning - new_form.amount
   request.user.profile.save()
   messages.success(request, f"Withdrawal Request Is Been Processed...")
   return redirect("core:withdrawal-request")

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