所以我有一个自定义表单字段，基本上检查我的数据库，看看给定的值（凭证代码）是否有效 . 我在 forms.py

class VoucherField(CharField):
    def to_python(self, value):
        if not value:
            return ""
        return value

    def validate(self, value):
        super(CharField, self).validate(value)

        vouchers = Vouchers.objects[0]
        if not value in vouchers.valid:
            raise ValidationError('This voucher is invalid or has been used already.')


class PurchaseForm(Form):
    voucher = VoucherField(required=True)    
    ...

并在views.py中

def orderHandler(request):
    form = PurchaseForm(request.POST)
    if form.is_valid():
        # Processes
    else:
        # Return errors

问题是form.is_valid（）行不断导致Django抛出 ValidationError 而不是捕获它并将消息保存到form.errors . 我不确定为什么会这样

python django forms validation