Question

在表单向导结束时，我有一个对象的自定义保存：

def done(self, form_list, **kwargs):

    (...)

    start = datetime.strptime(self.request.session['event_start'], '%Y-%m-%d %H:%M:%S')
    duration = datetime.strptime(self.request.session['duration'], '%H:%M:%S').time()

    EventInstance.objects.create(
        event=event_obj,
        start=start,
        duration=duration,
        recurring='0F',
    )

    (...)

我已经为最后一步手动编写了一个字符串，试图找出问题所在。当我尝试运行最终脚本时，回溯会使用recurring突出显示TypeError字段并告诉我Python expected string or bytes-like object。

这是我的模特：

class EventInstance(models.Model):
    event = models.ForeignKey(Event)
    start = models.DateTimeField()
    duration = models.DateTimeField()
    recurring = models.CharField(max_length=2)

event_obj是我在此过程中创建的Event对象。有人可以帮我理解这个错误吗？

回溯：

Traceback:
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\core\handlers\base.py" in get_response
  132.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\views\generic\base.py" in view
  71.             return self.dispatch(request, *args, **kwargs)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\formtools\wizard\views.py" in dispatch
  237.         response = super(WizardView, self).dispatch(request, *args, **kwargs)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\views\generic\base.py" in dispatch
  89.         return handler(request, *args, **kwargs)
File "C:\Users\Zeratul\Documents\otherlane\Otherlane\Events\views.py" in post
  181.                 return self.render_done(form, **kwargs)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\formtools\wizard\views.py" in render_done
  357.                                   **kwargs)
File "C:\Users\Zeratul\Documents\otherlane\Otherlane\Events\views.py" in done
  239.             recurring='0F',
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\manager.py" in manager_method
  127.                 return getattr(self.get_queryset(), name)(*args, **kwargs)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\query.py" in create
  348.         obj.save(force_insert=True, using=self.db)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\base.py" in save
  734.                        force_update=force_update, update_fields=update_fields)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\base.py" in save_base
  762.             updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\base.py" in _save_table
  846.             result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\base.py" in _do_insert
  885.                                using=using, raw=raw)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\manager.py" in manager_method
  127.                 return getattr(self.get_queryset(), name)(*args, **kwargs)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\query.py" in _insert
  920.         return query.get_compiler(using=using).execute_sql(return_id)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\sql\compiler.py" in execute_sql
  973.             for sql, params in self.as_sql():
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\sql\compiler.py" in as_sql
  931.                 for obj in self.query.objs
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\sql\compiler.py" in <listcomp>
  931.                 for obj in self.query.objs
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\sql\compiler.py" in <listcomp>
  929.                     ) for f in fields
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\fields\__init__.py" in get_db_prep_save
  710.                                       prepared=False)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\fields\__init__.py" in get_db_prep_value
  1482.             value = self.get_prep_value(value)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\fields\__init__.py" in get_prep_value
  1461.         value = super(DateTimeField, self).get_prep_value(value)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\fields\__init__.py" in get_prep_value
  1317.         return self.to_python(value)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\db\models\fields\__init__.py" in to_python
  1420.             parsed = parse_datetime(value)
File "C:\Users\Zeratul\Envs\otherlane\lib\site-packages\django\utils\dateparse.py" in parse_datetime
  93.     match = datetime_re.match(value)

Exception Type: TypeError at /events/post_event/
Exception Value: expected string or bytes-like object

修改

仔细观察追溯，似乎是＆＃34;持续时间＆＃34;领域。也许是因为我试图将时间保存为日期时间对象？

▼ Local vars
Variable    Value
__class__   <class 'django.db.models.fields.DateField'>
value   datetime.time(0, 30)
self    <django.db.models.fields.DateTimeField: duration>

Answer 1

它在最后一行突出显示，但显而易见的是，通过跟踪堆栈，它最终会出现在django的dateparse.py文件中，这表明它已经显示出来了。\ n \ n与datetime未正确解析的问题相关。回溯只会突出显示一个完整的语句，但由于您的create函数是一个多行语句，它会在recurring='0F'行上标记。换句话说，它告诉您，您的陈述EventInstance.objects.create(......)存在问题。

我认为您的duration字段为DateTimeField，但您的duration变量是datetime.time对象。您显然无法将time对象提供给datetime字段。

解决方案很简单，将duration字段更改为TimeField。

关于TimeField的Django doc。

Python / Django - 不接受字符串（＆＃39;期望字符串或类字节对象）

1 个答案: