解决Django表单验证不通过问题：使用form.errors进行诊断

import datetime
from django.shortcuts import render, redirect
from .models import Order, CartItem # 假设这些模型已定义
from .forms import OrderForm # 假设OrderForm已定义

def place_order(request, total=0, quantity=0):
    current_user = request.user

    cart_items = CartItem.objects.filter(user=current_user)
    cart_count = cart_items.count()
    if cart_count <= 0:
        return redirect('store')

    grand_total = 0
    tax = 0

    for cart_item in cart_items:
        total += (cart_item.product.price * cart_item.quantity)
        quantity += cart_item.quantity

    tax = (2 * total) / 100
    grand_total = total + tax

    if request.method == "POST":
        form = OrderForm(request.POST)
        if form.is_valid():
            # 表单验证成功，处理数据
            data = Order()
            data.user = current_user
            data.first_name = form.cleaned_data['first_name']
            data.last_name = form.cleaned_data['last_name']
            data.phone = form.cleaned_data['phone']
            data.email = form.cleaned_data['email']
            data.address_line_1 = form.cleaned_data['address_line_1']
            data.address_line_2 = form.cleaned_data['address_line_2']
            data.country = form.cleaned_data['country']
            data.state = form.cleaned_data['state']
            data.city = form.cleaned_data['city']
            data.order_note = form.cleaned_data['order_note']
            data.order_total = grand_total
            data.tax = tax
            data.ip = request.META.get('REMOTE_ADDR')
            data.save()

            yr = int(datetime.date.today().strftime('%Y'))
            dt = int(datetime.date.today().strftime('%d'))
            mt = int(datetime.date.today().strftime('%m'))
            d = datetime.date(yr, mt, dt)
            current_date = d.strftime("%Y%m%d")

            order_number = current_date + str(data.id)
            data.order_number = order_number
            data.save()

            order = Order.objects.get(
                user=current_user, is_ordered=False, order_number=order_number)
            context = {
                "order": order,
                "cart_items": cart_items,
                "total": total,
                "tax": tax,
                "grand_total": grand_total,
            }
            return render(request, "PixelCart/payments.html", context)
        else:
            # 表单验证失败，打印错误信息到控制台，并将错误信息传递给模板
            print("Form is NOT valid. Errors:", form.errors)
            # 重新渲染checkout页面，并显示错误信息
            context = {
                "form": form, # 将带有错误的表单实例传回模板
                "total": total,
                "tax": tax,
                "grand_total": grand_total,
                "cart_items": cart_items,
            }
            return render(request, "checkout.html", context) # 假设checkout.html是显示表单的页面
    else:
        # GET请求，初始化表单并渲染
        form = OrderForm()
        context = {
            "form": form,
            "total": total,
            "tax": tax,
            "grand_total": grand_total,
            "cart_items": cart_items,
        }
        return render(request, "checkout.html", context)

<form method="post">
    {% csrf_token %}

    <!-- 全局表单错误 (非字段特定错误) -->
    {% if form.non_field_errors %}
        <div class="alert alert-danger">
            {% for error in form.non_field_errors %}
                <p>{{ error }}</p>
            {% endfor %}
        </div>
    {% endif %}

    <div class="form-group">
        <label for="{{ form.first_name.id_for_label }}">First Name</label>
        <input type="text" name="{{ form.first_name.name }}" id="{{ form.first_name.id_for_label }}"
               value="{{ form.first_name.value|default_if_none:'' }}"
               class="form-control {% if form.first_name.errors %}is-invalid{% endif %}">
        {% if form.first_name.errors %}
            <div class="invalid-feedback">
                {% for error in form.first_name.errors %}
                    {{ error }}
                {% endfor %}
            </div>
        {% endif %}
    </div>

    <!-- 对其他字段重复上述模式 -->
    <div class="form-group">
        <label for="{{ form.email.id_for_label }}">Email</label>
        <input type="email" name="{{ form.email.name }}" id="{{ form.email.id_for_label }}"
               value="{{ form.email.value|default_if_none:'' }}"
               class="form-control {% if form.email.errors %}is-invalid{% endif %}">
        {% if form.email.errors %}
            <div class="invalid-feedback">
                {% for error in form.email.errors %}
                    {{ error }}
                {% endfor %}
            </div>
        {% endif %}
    </div>

    <button type="submit" class="btn btn-primary">Place Order</button>
</form>