嗨，我目前无法在Django信号函数中执行查询时跳过不显示错误（管理员）
我有这两个模型：
class TopUp(models.Model):
class Meta:
db_table = "topups"
verbose_name = 'Topup'
verbose_name_plural = 'Topups'
user = models.ForeignKey("backend.User", null=True, blank=True, related_name='user_optup', on_delete=models.CASCADE)
currency = models.ForeignKey("backend.Currency", null=True, blank=True, related_name='user_topup_currency', on_delete=models.SET_NULL)
TOPUP_METHOD_CHOICES = [
(0, 'fiat'),
(1, 'chain')
]
method = models.PositiveSmallIntegerField("Method", choices=TOPUP_METHOD_CHOICES, default=0)
amount = models.DecimalField("Amount", max_digits=65, decimal_places=0, default=0)
TOPUP_STATUS_CHOICES = [
(0, 'Pending'),
(1, 'Approved'),
(100, 'Rejected'),
]
status = models.PositiveSmallIntegerField("Status", choices=TOPUP_STATUS_CHOICES, default=0)
class UserBalance(models.Model):
class Meta:
db_table = "user_balances"
verbose_name = 'User Balance'
verbose_name_plural = 'User Balance'
user = models.ForeignKey("backend.User", null=True, blank=True, related_name='user_balance', on_delete=models.CASCADE)
currency = models.ForeignKey("backend.Currency", null=True, blank=True, related_name='user_balance_currency', on_delete=models.SET_NULL)
balance = models.DecimalField("Balance", max_digits=65, decimal_places=0, default=0)
该逻辑在Django admin上，如果状态在TopUps上发生了更改（也向帐户记录中添加了钱），它将处理用户余额的余额如果状态更改为1（已批准），则该币种的用户余额增加，如果拒绝，则还原，依此类推...
我的管理员：
class TopUpsAdmin(admin.ModelAdmin):
list_display = ('get_phone_number',)
def get_phone_number(self, obj):
return obj.user.phone_number
get_phone_number.short_description = 'User'
get_phone_number.admin_order_field = 'user_phone_number'
def get_readonly_fields(self, request, obj=None):
return ('id', )
def save_model(self, request, obj, form, change):
update_fields = []
# True if something changed in model
# Note that change is False at the very first time
if change:
if form.initial['status'] != form.cleaned_data['status']:
update_fields.append('status')
obj.save(update_fields=update_fields)
else:
obj.save()
else:
obj.save()
pass
admin.site.register(TopUp, TopUpsAdmin)
这是我在django的管理站点（更改视图）上更改状态时要处理的信号：
@receiver(pre_save, sender=TopUp)
def handle_balance_on_topups_status_updated(sender, instance, update_fields, **kwargs):
if update_fields is not None:
if 'status' in update_fields:
try:
old_topups = TopUp.objects.get(pk=instance.id)
user = UserBalance.objects.get(user=instance.user, currency=instance.currency)
if (old_topups.status == 0) and (instance.status == 1):
user.balance += instance.amount
user.save()
elif (old_topups.status == 1) and (instance.status == 100) and (user.balance > 0):
user.balance -= instance.amount
user.save()
elif (old_topups.status == 1) and (instance.status == 0) and (user.balance > 0):
user.balance -= instance.amount
user.save()
elif (old_topups.status == 100) and (instance.status == 1):
user.balance += instance.amount
user.save()
except TopUp.DoesNotExist or UserBalance.DoesNotExist:
pass
如果TopUp或UserBalane查询失败并通过传递信号，我会写一个try-catch以便在管理页面上不显示错误，但是当我尝试批准TopUp并使用UserBalance没有的货币时，我的管理页面仍然显示错误。
追踪错误：
Traceback (most recent call last):
web_1 | File "/usr/local/lib/python3.7/site-packages/django/core/handlers/exception.py", line 34, in inner
web_1 | response = get_response(request)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/core/handlers/base.py", line 115, in _get_response
web_1 | response = self.process_exception_by_middleware(e, request)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/core/handlers/base.py", line 113, in _get_response
web_1 | response = wrapped_callback(request, *callback_args, **callback_kwargs)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/contrib/admin/options.py", line 606, in wrapper
web_1 | return self.admin_site.admin_view(view)(*args, **kwargs)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/utils/decorators.py", line 142, in _wrapped_view
web_1 | response = view_func(request, *args, **kwargs)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/views/decorators/cache.py", line 44, in _wrapped_view_func
web_1 | response = view_func(request, *args, **kwargs)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/contrib/admin/sites.py", line 223, in inner
web_1 | return view(request, *args, **kwargs)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/contrib/admin/options.py", line 1648, in change_view
web_1 | return self.changeform_view(request, object_id, form_url, extra_context)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/utils/decorators.py", line 45, in _wrapper
web_1 | return bound_method(*args, **kwargs)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/utils/decorators.py", line 142, in _wrapped_view
web_1 | response = view_func(request, *args, **kwargs)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/contrib/admin/options.py", line 1529, in changeform_view
web_1 | return self._changeform_view(request, object_id, form_url, extra_context)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/contrib/admin/options.py", line 1572, in _changeform_view
web_1 | self.save_model(request, new_object, form, not add)
web_1 | File "/app/backend/admin.py", line 308, in save_model
web_1 | obj.save(update_fields=update_fields)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/db/models/base.py", line 741, in save
web_1 | force_update=force_update, update_fields=update_fields)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/db/models/base.py", line 766, in save_base
web_1 | update_fields=update_fields,
web_1 | File "/usr/local/lib/python3.7/site-packages/django/dispatch/dispatcher.py", line 175, in send
web_1 | for receiver in self._live_receivers(sender)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/dispatch/dispatcher.py", line 175, in <listcomp>
web_1 | for receiver in self._live_receivers(sender)
web_1 | File "/app/backend/models.py", line 389, in handle_balance_on_topups_status_updated
web_1 | user = UserBalance.objects.get(user=instance.user, currency=instance.currency)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/db/models/manager.py", line 82, in manager_method
web_1 | return getattr(self.get_queryset(), name)(*args, **kwargs)
web_1 | File "/usr/local/lib/python3.7/site-packages/django/db/models/query.py", line 408, in get
web_1 | self.model._meta.object_name
web_1 | backend.models.UserBalance.DoesNotExist: UserBalance matching query does not exist.
我希望它不会显示错误，但仍将更改后的状态保存在管理页面上，但用户余额不会受到影响（因为使用该货币的UserBalance不存在）
为什么我的try-except无法在信号中起作用？
要使用一个multiple exception classes语句捕获except，请使用parentheses列出异常类：