Question

我正在尝试更新int模型中的Django字段之一。

但是在更新此字段时出现以下错误。

（这是在ipython中使用python manage.py shell）

# this is what I m trying to do
>> a = download.objects.get(id=1)
>> a.url = ""
>> a.save() # raises an error

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
/usr/local/lib/python2.7/dist-packages/django/core/management/commands/shell.pyc in <module>()
----> 1 a.save()

/usr/local/lib/python2.7/dist-packages/django/db/models/base.pyc in save(self, force_insert, force_update, using, update_fields)
    544 
    545         self.save_base(using=using, force_insert=force_insert,
--> 546                        force_update=force_update, update_fields=update_fields)
    547     save.alters_data = True
    548 

/usr/local/lib/python2.7/dist-packages/django/db/models/base.pyc in save_base(self, raw, cls, origin, force_insert, force_update, using, update_fields)
    624                         values = [(f, None, (raw and getattr(self, f.attname) or f.pre_save(self, False))) for f in non_pks]
    625                         if values:
--> 626                             rows = manager.using(using).filter(pk=pk_val)._update(values)
    627                             if force_update and not rows:
    628                                 raise DatabaseError("Forced update did not affect any rows.")

/usr/local/lib/python2.7/dist-packages/django/db/models/query.pyc in _update(self, values)
    603         query.add_update_fields(values)
    604         self._result_cache = None
--> 605         return query.get_compiler(self.db).execute_sql(None)
    606     _update.alters_data = True
    607 

/usr/local/lib/python2.7/dist-packages/django/db/models/sql/compiler.pyc in execute_sql(self, result_type)
   1012         related queries are not available.
   1013         """
-> 1014         cursor = super(SQLUpdateCompiler, self).execute_sql(result_type)
   1015         rows = cursor and cursor.rowcount or 0
   1016         is_empty = cursor is None

/usr/local/lib/python2.7/dist-packages/django/db/models/sql/compiler.pyc in execute_sql(self, result_type)
    828         """
    829         try:
--> 830             sql, params = self.as_sql()
    831             if not sql:
    832                 raise EmptyResultSet

/usr/local/lib/python2.7/dist-packages/django/db/models/sql/compiler.pyc in as_sql(self)
    977                 val = val.prepare_database_save(field)
    978             else:
--> 979                 val = field.get_db_prep_save(val, connection=self.connection)
    980 
    981             # Getting the placeholder for the field.

/usr/local/lib/python2.7/dist-packages/django/db/models/fields/__init__.pyc in get_db_prep_save(self, value, connection)
    302         """
    303         return self.get_db_prep_value(value, connection=connection,
--> 304                                       prepared=False)
    305 
    306     def get_prep_lookup(self, lookup_type, value):

/usr/local/lib/python2.7/dist-packages/jsonfield/fields.pyc in get_db_prep_value(self, value, connection, prepared)
     47         if isinstance(value, basestring):
     48             return value
---> 49         return json.dumps(value, **self.dump_kwargs)
     50 
     51     def value_to_string(self, obj):

/usr/lib/python2.7/dist-packages/simplejson/__init__.pyc in dumps(obj, skipkeys, ensure_ascii, check_circular, allow_nan, cls, indent, separators, encoding, default, use_decimal, namedtuple_as_object, tuple_as_array, **kw)
    294         namedtuple_as_object=namedtuple_as_object,
    295         tuple_as_array=tuple_as_array,
--> 296         **kw).encode(obj)
    297 
    298 

TypeError: __init__() got an unexpected keyword argument 'namedtuple_as_object'

有人可以建议我，这里出了什么问题？

Answer 1

你在该模型中有一个json字段，你遇到了{em> simplejson 的问题documented in Django 1.5 release notes as a potential issue。

如果您通过pip uninstall simplejson安装，则需要卸载 simplejson （pip）。这样Django将使用Python的内置版本，它没有那些兼容性问题。

尝试保存模型Django 1.5时出现`namedtuple_as_object`错误

1 个答案: