错误：“字典更新序列元素＃0的长度为1；在Django 1.4上需要2

我在django 1.4上收到一条错误消息：

字典更新序列元素＃0的长度为1；2个为必填项

[编辑]

当我尝试使用模板标签时发生了这种情况：`{％for v in values％}：

dictionary update sequence element #0 has length 1; 2 is required

Request Method:     GET
Request URL:    ...
Django Version:     1.4.5
Exception Type:     ValueError
Exception Value:    

dictionary update sequence element #0 has length 1; 2 is required

Exception Location:     /usr/local/lib/python2.7/dist-packages/djorm_hstore/fields.py in __init__, line 21
Python Executable:  /usr/bin/uwsgi-core
Python Version:     2.7.3
Python Path:    

['/var/www/',
 '.',
 '',
 '/usr/lib/python2.7',
 '/usr/lib/python2.7/plat-linux2',
 '/usr/lib/python2.7/lib-tk',
 '/usr/lib/python2.7/lib-old',
 '/usr/lib/python2.7/lib-dynload',
 '/usr/local/lib/python2.7/dist-packages',
 '/usr/lib/python2.7/dist-packages',
 '/usr/lib/python2.7/dist-packages/PIL',
 '/usr/lib/pymodules/python2.7']

Server time:    sam, 13 Jul 2013 16:15:45 +0200
Error during template rendering

In template /var/www/templates/app/index.html, error at line 172
dictionary update sequence element #0 has length 1; 2 is required

172     {% for product in products %}

Traceback Switch to copy-and-paste view

/usr/lib/python2.7/dist-packages/django/core/handlers/base.py in get_response

                            response = callback(request, *callback_args, **callback_kwargs)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/contrib/auth/decorators.py in _wrapped_view

                    return view_func(request, *args, **kwargs)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/views/decorators/http.py in inner

                return func(request, *args, **kwargs)

    ...
▶ Local vars
./app/views.py in index

            context_instance=RequestContext(request))

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/shortcuts/__init__.py in render_to_response

        return HttpResponse(loader.render_to_string(*args, **kwargs), **httpresponse_kwargs)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/loader.py in render_to_string

            return t.render(context_instance)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/base.py in render

                return self._render(context)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/base.py in _render

            return self.nodelist.render(context)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/base.py in render

                    bit = self.render_node(node, context)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/debug.py in render_node

                return node.render(context)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/loader_tags.py in render

            return compiled_parent._render(context)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/base.py in _render

            return self.nodelist.render(context)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/base.py in render

                    bit = self.render_node(node, context)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/debug.py in render_node

                return node.render(context)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/loader_tags.py in render

                result = block.nodelist.render(context)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/base.py in render

                    bit = self.render_node(node, context)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/debug.py in render_node

                return node.render(context)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/template/defaulttags.py in render

            len_values = len(values)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/core/paginator.py in __len__

            return len(self.object_list)

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/db/models/query.py in __len__

                    self._result_cache = list(self.iterator())

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/db/models/query.py in iterator

                        obj = model(*row[index_start:aggregate_start])

    ...
▶ Local vars
/usr/lib/python2.7/dist-packages/django/db/models/base.py in __init__

                    setattr(self, field.attname, val)

    ...
▶ Local vars
/usr/local/lib/python2.7/dist-packages/djorm_hstore/fields.py in __set__

                value = self.field._attribute_class(value, self.field, obj)

    ...
▶ Local vars
/usr/local/lib/python2.7/dist-packages/djorm_hstore/fields.py in __init__

            super(HStoreDictionary, self).__init__(value, **params)

    ...
▶ Local vars

当我尝试访问hstore queryset时，也会发生这种情况：

[编辑]

Traceback (most recent call last):
File "manage.py", line 14, in <module>
    execute_manager(settings)

File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 459, in execute_manager
    utility.execute()

File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 382, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)

File "/usr/local/lib/python2.7/dist-packages/django/core/management/base.py", line 196, in run_from_argv
    self.execute(*args, **options.__dict__)

File "/usr/local/lib/python2.7/dist-packages/django/core/management/base.py", line 232, in execute
    output = self.handle(*args, **options)

File "/home/name/workspace/project/app/data/commands/my_command.py", line 60, in handle
    item_id = tmp[0].id,

File "/usr/local/lib/python2.7/dist-packages/django/db/models/query.py", line 207, in __getitem__
    return list(qs)[0]

File "/usr/local/lib/python2.7/dist-packages/django/db/models/query.py", line 87, in __len__
    self._result_cache.extend(self._iter)

File "/usr/local/lib/python2.7/dist-packages/django/db/models/query.py", line 301, in iterator
    obj = model(*row[index_start:aggregate_start])

File "/usr/local/lib/python2.7/dist-packages/django/db/models/base.py", line 300, in __init__
    setattr(self, field.attname, val)

File "/usr/local/lib/python2.7/dist-packages/djorm_hstore/fields.py", line 38, in __set__
    value = self.field._attribute_class(value, self.field, obj)

File "/usr/local/lib/python2.7/dist-packages/djorm_hstore/fields.py", line 21, in __init__
    super(HStoreDictionary, self).__init__(value, **params)

ValueError: dictionary update sequence element #0 has length 1; 2 is required

代码是：

tmp = Item.objects.where(HE("kv").contains({'key':value}))

if tmp.count() > 0:

    item_id = tmp[0].id,

我只是在尝试获取价值。我不理解“更新顺序”消息。当我使用游标而不是hstore queryset时，该函数有效。错误也来自模板渲染。我刚刚重新启动uwsgi，一切正常，但是稍后又返回了错误。

[编辑]

有人知道吗？

刚遇到这个问题。我不知道是不是碰到了您的代码，但是对我而言，根本原因是因为我忘记name=了url（或path在Django 2.0+中）函数调用的最后一个参数。

例如，以下函数引发问题中的错误：

url(r'^foo/(?P<bar>[A-Za-z]+)/$', views.FooBar.as_view(), 'foo')
path('foo/{slug:bar}/', views.FooBar, 'foo')

但是这些实际上有效：

url(r'^foo/(?P<bar>[A-Za-z]+)/$', views.FooBar.as_view(), name='foo')
path('foo/{slug:bar}/', views.FooBar, name='foo')

回溯之所以无济于事，是因为Django在内部希望将给定的位置参数解析为关键字 arguments kwargs，并且由于字符串是可迭代的，因此非典型代码路径开始展开。始终name=在您的网址上使用！

我在弄乱字符串和字典时遇到了这个错误。

dict1 = {'taras': 'vaskiv', 'iruna': 'vaskiv'}
str1 = str(dict1)
dict(str1)
*** ValueError: dictionary update sequence element #0 has length 1; 2 is required

因此，您实际上要做的是从字符串中获取字典：

dic2 = eval(str1)
dic2
{'taras': 'vaskiv', 'iruna': 'vaskiv'}

或者出于安全考虑，我们可以使用literal_eval

from ast import literal_eval

尝试执行以下操作时，将引发问题错误：

>>> a_dictionary = {}
>>> a_dictionary.update([[1]])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: dictionary update sequence element #0 has length 1; 2 is required

除非显示完整的追溯代码，否则很难说出代码中的原因。

当我忘记将关键字参数名称传递给url（）函数时，我遇到了上述问题。

错误代码

 url(r"^testing/$", views.testing, "testing")

代码无错误

url(r"^testing/$", views.testing, name="testing")

所以最后我以这种方式消除了上面的错误。您的情况可能有所不同。因此，请在urls.py中检查您的网址格式。

解”

将关键字参数名称（其值作为视图名称）传递给例如home或home-view等。url()的功能。

引发错误»

url(r'^home$', 'common.views.view1', 'home'),

正确”

url(r'^home$', 'common.views.view1', name='home'),

这是重现的错误。

>>> d = {}
>>> d.update([(1,)])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: dictionary update sequence element #0 has length 1; 2 is required
>>> 
>>> d
{}
>>> 
>>> d.update([(1, 2)])
>>> d
{1: 2}
>>> 
>>> d.update('hello_some_string')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>  
ValueError: dictionary update sequence element #0 has length 1; 2 is required
>>> 

如果给定序列，并且任何元素长度为1且需要两个，那么我们将得到这种错误。参见上面的代码。第一次给序列赋予元组，其长度为1，那么我们得到了错误并且字典没有更新。第二次我给内部元组添加了两个元素，字典得到了更新。

我遇到了同样的问题，发现这是由于参数错误造成的。在中views.py，我使用了：

return render(request, 'demo.html',{'items', items})    

但我发现了问题：{'items', items}。进行更改以{'items': items}解决问题。

就我而言，我get_context_data的观点之一是return render(self.request, 'es_connection_error.html', {'error':error});在try / catch块中返回而不是返回context

错误应该与参数有关。请验证params是否为字典对象。如果只是参数列表/元组，则仅使用一个*（*params）而不是两个*（**params）。这会将列表/元组爆炸为适当数量的参数。

或者，如果参数来自代码的其他部分作为JSON文件，请这样做json.loads(params)，因为JSON对象有时表现为字符串，因此您需要使用来自字符串的负载（负载）将其作为JSON。

super(HStoreDictionary, self).__init__(value, **params)

希望这可以帮助！

尝试使用错误类型的参数调用update方法时遇到此问题。预期的结果是：

{'foo': True}

通过的是：

{'foo': "True"}

确保您检查传递的所有参数均为预期类型。

您发送的参数不正确；它应该是dictionary object：

• 错误： func(a=r)

• 正确： func(a={'x':y})

我也有类似的问题。解决方法很简单。只是不要尝试在值中输入NULL或None值，否则您可能必须使用类似这样的东西
dic.update([(key,value)])