python - 删除后的Django无限循环
问题描述
也许以下是一个 django 错误:
我有三个模型,而一个模型有一个自定义__init__
方法:
from django.db import models
class Foo(models.Model):
my_foo = models.CharField(max_length=1000)
class Bar(models.Model):
bar1 = models.CharField(max_length=1000, default="")
bar2 = models.BooleanField(default=False)
foo = models.ForeignKey(Foo, on_delete=models.CASCADE)
def __init__(self, *args, **kwargs):
super(Bar, self).__init__(*args, **kwargs)
print("check")
self._original_bar1 = self.bar1
self._original_bar2 = self.bar2
class Baz(models.Model):
bar = models.ForeignKey(Bar, on_delete=models.CASCADE)
创建一个 Foo 对象和一个相应的 Bar 对象(通过管理界面)可以正常工作。但是,当我删除 Foo 对象时,这会导致该方法无限循环__init__
。
如果我将模型稍微重写为
from django.db import models
class Foo(models.Model):
my_foo = models.CharField(max_length=1000)
class AbstractBar2(models.Model):
bar2 = models.BooleanField(default=False)
def __init__(self, *args, **kwargs):
super(AbstractBar2, self).__init__(*args, **kwargs)
print("check")
self._original_bar2 = self.bar2
class Meta:
abstract = True
class AbstractBar1(models.Model):
bar1 = models.CharField(max_length=1000, default="")
def __init__(self, *args, **kwargs):
super(AbstractBar1, self).__init__(*args, **kwargs)
print("check")
self._original_bar1 = self.bar1
class Meta:
abstract = True
class Bar(AbstractBar1, AbstractBar2):
foo = models.ForeignKey(Foo, on_delete=models.CASCADE)
class Baz(models.Model):
bar = models.ForeignKey(Bar, on_delete=models.CASCADE)
它出错了
Fatal Python error: _Py_CheckRecursiveCall: Cannot recover from stack overflow.
Python runtime state: initialized
Current thread 0x000035d0 (most recent call first):
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\fields\__init__.py", line 807 in get_prep_value
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\fields\__init__.py", line 1770 in get_prep_value
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\lookups.py", line 76 in get_prep_lookup
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\lookups.py", line 24 in __init__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\sql\query.py", line 1165 in build_lookup
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\sql\query.py", line 1319 in build_filter
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\sql\query.py", line 1377 in _add_q
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\sql\query.py", line 1358 in add_q
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 969 in _filter_or_exclude_inplace
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 962 in _filter_or_exclude
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 942 in filter
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\manager.py", line 85 in manager_method
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 623 in refresh_from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query_utils.py", line 149 in __get__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 26 in __init__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 513 in from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 71 in __iter__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 1308 in _fetch_all
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 269 in __len__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 425 in get
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 635 in refresh_from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query_utils.py", line 149 in __get__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 14 in __init__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 24 in __init__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 513 in from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 71 in __iter__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 1308 in _fetch_all
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 269 in __len__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 425 in get
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 635 in refresh_from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query_utils.py", line 149 in __get__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 26 in __init__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 513 in from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 71 in __iter__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 1308 in _fetch_all
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 269 in __len__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 425 in get
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 635 in refresh_from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query_utils.py", line 149 in __get__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 14 in __init__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 24 in __init__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 513 in from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 71 in __iter__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 1308 in _fetch_all
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 269 in __len__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 425 in get
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 635 in refresh_from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query_utils.py", line 149 in __get__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 26 in __init__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 513 in from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 71 in __iter__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 1308 in _fetch_all
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 269 in __len__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 425 in get
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 635 in refresh_from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query_utils.py", line 149 in __get__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 14 in __init__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 24 in __init__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 513 in from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 71 in __iter__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 1308 in _fetch_all
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 269 in __len__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 425 in get
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 635 in refresh_from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query_utils.py", line 149 in __get__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 26 in __init__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 513 in from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 71 in __iter__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 1308 in _fetch_all
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 269 in __len__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 425 in get
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 635 in refresh_from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query_utils.py", line 149 in __get__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 14 in __init__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 24 in __init__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 513 in from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 71 in __iter__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 1308 in _fetch_all
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 269 in __len__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 425 in get
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 635 in refresh_from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query_utils.py", line 149 in __get__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 26 in __init__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 513 in from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 71 in __iter__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 1308 in _fetch_all
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 269 in __len__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 425 in get
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 635 in refresh_from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query_utils.py", line 149 in __get__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 14 in __init__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 24 in __init__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 513 in from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 71 in __iter__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 1308 in _fetch_all
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 269 in __len__
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query.py", line 425 in get
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\base.py", line 635 in refresh_from_db
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\db\models\query_utils.py", line 149 in __get__
File "C:\Users\name\PycharmProjects\djangoTest\foobar\models.py", line 26 in __init__
...
Thread 0x00000a60 (most recent call first):
File "C:\Users\name\AppData\Local\Programs\Python\Python39\lib\selectors.py", line 315 in _select
File "C:\Users\name\AppData\Local\Programs\Python\Python39\lib\selectors.py", line 324 in select
File "C:\Users\name\AppData\Local\Programs\Python\Python39\lib\socketserver.py", line 232 in serve_forever
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\core\servers\basehttp.py", line 216 in run
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\core\management\commands\runserver.py", line 139 in inner_run
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\utils\autoreload.py", line 53 in wrapper
File "C:\Users\name\AppData\Local\Programs\Python\Python39\lib\threading.py", line 888 in run
File "C:\Users\name\AppData\Local\Programs\Python\Python39\lib\threading.py", line 950 in _bootstrap_inner
File "C:\Users\name\AppData\Local\Programs\Python\Python39\lib\threading.py", line 908 in _bootstrap
Thread 0x00000c7c (most recent call first):
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\utils\autoreload.py", line 374 in tick
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\utils\autoreload.py", line 324 in run_loop
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\utils\autoreload.py", line 318 in run
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\utils\autoreload.py", line 603 in start_django
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\utils\autoreload.py", line 618 in run_with_reloader
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\core\management\commands\runserver.py", line 103 in run
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\core\management\commands\runserver.py", line 96 in handle
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\core\management\base.py", line 371 in execute
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\core\management\commands\runserver.py", line 61 in execute
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\core\management\base.py", line 330 in run_from_argv
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\core\management\__init__.py", line 395 in execute
File "C:\Users\name\PycharmProjects\global39\djangoTest\lib\site-packages\django\core\management\__init__.py", line 401 in execute_from_command_line
File "C:\Users\name\PycharmProjects\djangoTest\manage.py", line 18 in main
File "C:\Users\name\PycharmProjects\djangoTest\manage.py", line 22 in <module>
Process finished with exit code -1
有任何想法吗?
解决方案
此行为已多次报告给 Django 问题跟踪器(#31435、#31475、# 32660 )。
建议应该使用完成自定义模型加载,Model.from_db()
并且还有一些可用的文档如何做到这一点。如果这不可能,self.__dict__.get('attribute')
则提到使用 ,作为在覆盖方法中调用的替代__init__
方法。
这在处理https://stackoverflow.com/a/1793323/2159075中建议的多个属性时尤其重要
推荐阅读
- r - 通过 tidyverse 使用粘贴和数字索引按列应用函数
- c++ - 显示与 main.cpp 不同的类
- reactjs - 在 gatsbyJs 中处理用户
- php - 使用需要交互的终端运行php代码
- java - MySQL - Java 语法错误。为什么这不起作用?
- javascript - 无法通过 Rest API 使用我在 React Native 中构建的移动应用程序访问 Cosmos DB
- go - 非appconf beego项目中如何设置项目httpport?
- c++ - 如何关闭第二个窗口(WIN32),然后重新打开它
- reactjs - 刷新后如何将数据保存在localStorage中?
- java - 如何处理具有不同参数的构造函数