Django：将 ChoiceField 选项作为位置参数传递给表单的 `__init__()` 会导致 AttributeError答案

【问题标题】：Django: passing ChoiceField choices to form's `__init__()` as positional argument causes AttributeErrorDjango：将 ChoiceField 选项作为位置参数传递给表单的 `__init__()` 会导致 AttributeError
【发布时间】：2017-01-16 16:14:58
【问题描述】：

我正在尝试将 views.py 中的参数传递给 forms.py 以使用 CheckboxSelectMultiple 小部件创建 ChoiceField，但渲染失败。

异常类型：AttributeError 异常值：'list' 对象没有属性'get'。

请你看看下面，并说明我做错了什么:(

提前感谢您的帮助。

forms.py：

class TestSubmitForm(forms.Form):
    tests = forms.ChoiceField()

    def __init__(self,*args,**kwargs):
        self.testList = args[0]
        super(TestSubmitForm,self).__init__(*args,**kwargs)
        self.fields['tests'].widget = forms.CheckboxSelectMultiple()
        self.fields['tests'].choices = self.testList

views.py

def index(request):
    tc_obj_form = [("","1"),("","2"),("",3")]
    tests = TestSubmitForm(tc_obj_form)
    return render(request, 'index.html',{'tests':tests})

index.html

<form action="." method="POST">
    <table >
        {% csrf_token %}
        {{ tests }}
    </table>
    <input type="submit" value="Submit"/>
</form>

堆栈跟踪：

Traceback: File "/local/User/demo/web/venv/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  111.                     response = wrapped_callback(request, *callback_args, **callback_kwargs) File "/local/User/demo/web/apps/Lcloud/views.py" in index
  94.           return render(request, 'Lcloud/index.html',
  ...
  135.         return self.as_table() File "/local/User/demo/web/venv/lib/python2.7/site-packages/django/forms/forms.py" in as_table
  257.             errors_on_separate_row=False) File "/local/User/demo/web/venv/lib/python2.7/site-packages/django/forms/forms.py" in _html_output
  181.         top_errors = self.non_field_errors()  # Errors that should be displayed above all fields. File "/local/User/demo/web/venv/lib/python2.7/site-packages/django/forms/forms.py" in non_field_errors
  283.         return self.errors.get(NON_FIELD_ERRORS, self.error_class()) File "/local/User/demo/web/venv/lib/python2.7/site-packages/django/forms/forms.py" in errors
  154.             self.full_clean() File "/local/User/demo/web/venv/lib/python2.7/site-packages/django/forms/forms.py" in full_clean
  353.         self._clean_fields() File "/local/User/demo/web/venv/lib/python2.7/site-packages/django/forms/forms.py" in _clean_fields
  362.             value = field.widget.value_from_datadict(self.data, self.files, self.add_prefix(name)) File "/local/User/demo/web/venv/lib/python2.7/site-packages/django/forms/widgets.py" in value_from_datadict
  585.         return data.get(name, None)

Exception Type: AttributeError at /Lcloud/ Exception Value: 'list' object has no attribute 'get'

【问题讨论】：

标签： python django django-forms

【解决方案1】：

如下更改表单的__init__()：

def __init__(self, testList, args,**kwargs):
    self.testList = testList
    super(TestSubmitForm,self).__init__(*args,**kwargs)  # testList not in args!
    # ...

问题在于forms.Form 的__init__()（您通过super(...) 调用）需要一个类似dict 的对象作为其第一个位置参数。通常，如果提供，那将是一个QueryDict 实例，如request.POST 或某事。类似。

【讨论】：