Python 隐藏django表单字段的无值

我的新闻应用程序上有一个“结束日期”字段，这是一个临时字段。 当一个作者编辑一个新文档并删除结束日期时，我在模型中将结束日期设置为无

我的问题是，该字段在下次编辑时显示值“None”，而不是仅为空

这是我的领域：

型号.py

end_date = models.DateTimeField(null=True, blank=True)

end_date = forms.CharField(label='', required=False, widget=forms.DateTimeInput(attrs={'class': 'form-control', 'format': 'DD, d MM yy', 'placeholder': _('End date')}))

 if news_form.cleaned_data['end_date'] == '' :
    edited_new.end_date = None 
 edited_new.save()

forms.py

end_date = models.DateTimeField(null=True, blank=True)

end_date = forms.CharField(label='', required=False, widget=forms.DateTimeInput(attrs={'class': 'form-control', 'format': 'DD, d MM yy', 'placeholder': _('End date')}))

 if news_form.cleaned_data['end_date'] == '' :
    edited_new.end_date = None 
 edited_new.save()

在我看来，转让：

视图.py

end_date = models.DateTimeField(null=True, blank=True)

end_date = forms.CharField(label='', required=False, widget=forms.DateTimeInput(attrs={'class': 'form-control', 'format': 'DD, d MM yy', 'placeholder': _('End date')}))

 if news_form.cleaned_data['end_date'] == '' :
    edited_new.end_date = None 
 edited_new.save()

编辑：

这是我的模板：

news.html

        <form action="#" method="post" role="form" id="news-form">{% csrf_token %}
        {{ news_form.media }}
        <div class="col-xs-12">
            <div class="panel panel-primary">
                <div class="panel-heading">
                    <div class="row">
                        <div class="col-xs-12 col-md-6">
                            <h2 class="panel-title">{% trans "Add or edit news" %}</h2>
                        </div>
                        <div class="col-xs-12 col-md-6">
                            <div class="pull-right">
                                <a href="#" class="btn btn-secondary cancel"><span class="glyphicon glyphicon-floppy-remove"></span> {% trans "Cancel" %}</a>
                                <button type="submit" class="btn btn-primary form-btn save"><span class="glyphicon glyphicon-floppy-saved"></span><span class="button-text"> {% trans "Save" %}</span></button>
                            </div>
                        </div>
                    </div>
                </div>
                <div class="panel-body">
                    <div class="row">
                        <div class="col-xs-12 col-md-6">
                            {{ news_form.title }}
                        </div>
                        <div class="col-xs-4 col-md-2">
                            {% trans 'Tag' %}
                        </div>
                        <div class="col-xs-8 col-md-4">
                            {{ news_form.tag }}
                        </div>
                    </div>
                    <div class="row">
                        <div class="col-xs-12 no-label-field redactor-field">
                            {{ news_form.message }}
                        </div>
                    </div>
                    <div class="row">
                        <div class="col-xs-6 date-field no-label-field">
                            <div class="form-group">
                                <div class='input-group date datetimepicker'>
                                    {{ news_form.start_date }}
                                    <span class="input-group-addon"><span class="glyphicon glyphicon-calendar"></span>
                                    </span>
                                </div>
                            </div>
                        </div>
                        <div class="col-xs-6 date-field no-label-field">
                            <div class="form-group">
                                <div class='input-group date datetimepicker'>
                                    {{ news_form.end_date }}
                                    <span class="input-group-addon"><span class="glyphicon glyphicon-calendar"></span>
                                    </span>
                                </div>
                            </div>
                        </div>
                    </div>
                    <div class="row">
                        <div class="col-xs-12">
                            {{ news_form.active }} {% trans 'Activate the news' %}
                        </div>
                    </div>
                </div>
            </div>
        </div>
        <span style="display:none;">{{ news_form.id }}</span>
    </form>

{%csrf\u令牌%}
{{news_form.media}
{%trans“添加或编辑新闻”%}
{%trans“保存”%}
{{news_form.title}
{%trans'标记“%”
{{news_form.tag}
{{news_form.message}
{{news\u form.start\u date}
{{news\u form.end\u date}
{{news\u form.active}{%trans'激活新闻“%”
{{news_form.id}

如果自Django 1.3以来没有可用的过滤器，则可以使用过滤器

默认值，它仅适用于
无的值

{{ news_form.end_date|default_if_none:'' }}

你能发布模板中的相关片段吗？我已经编辑了我的问题。谢谢，它只对值有效，对表单字段无效，不是吗？它只对值有效：{{{news\u form.end\u date.value{124; default\u if\u none:'}}而且它对空值无效。只有在“{{news_form.end_date.value{124; default_if_none:'a'}”中有内容时才有效。这将有效为什么“none”的默认值不是“”（空）？