反向 'new_project'，未找到参数 '('',)'。尝试了 1 种模式：['new_project/$']

Question

traceback picture

我刚刚学会使用 python 和 Django 2 周，我正在尝试建立一个待办事项列表。我遇到了一个错误，我可能需要一些建议。

在待办列表中，有一个所有项目的页面，当你点击进入一个项目时，会有一个待办列表。我试图通过这些代码实现添加新项目功能，但是出现returns如题所示的错误，网上查了很多答案，大部分是因为在 HTML 文件中不恰当地引入了 URL 或者当你在 views.py 中指定了比表格更多的值而你忘记将它们放在 url.

后面

我仍然无法理解该错误，如果您能给我一些提示，指出我可能出错的地方，我将不胜感激。谢谢

urls.py

app_name = 'todo_lists'
urlpatterns = [
    # homepage
    path('', views.index, name='index'),
    # page that shows all projects
    path('projects/', views.projects, name='projects'),
    # details of a project
    path('projects/<int:project_id>/', views.project, name='project'),
    # add a new project
    path('new_project/', views.new_project, name='new_project'),

views.py

def new_project(request):
    # add new project
    
    if request.method != 'POST':
        # if not submit then create a new form for user
        form = ProjectForm()
    else:
        form = ProjectForm(request.POST)
        if form.is_valid():
            
            form.save()
            return HttpResponseRedirect(reverse('todo_lists:projects'))
# team', 'name', 'due_date', 'project_code', 'details
    context = {'form': form}
    return render(request, 'todo_lists/new_project.html', context)

models.py

class Project(models.Model):
    
    name = models.CharField(max_length=20) 
    create_date = models.DateTimeField(auto_now_add=True)
    due_date = models.DateTimeField(default=datetime.datetime.now)
    project_code = models.CharField(max_length=20)
    details = models.TextField()
    team = models.CharField(max_length=200)

    def __str__(self):
        return self.details

forms.py

class ProjectForm(forms.ModelForm):
    class Meta:
        model = Project
        fields = ['team', 'name', 'due_date', 'project_code', 'details']
        widgets = {
                    'start_date': forms.SelectDateWidget(),
                    'due_date': forms.SelectDateWidget(),
        }

new_project.html

<!doctype html>
{% extends "todo_lists/base.html" %}

{% block content %}
    <p>Add a new project:</p>

    <form action="{% url 'todo_lists:new_project' %}" method="post">
        {% csrf_token %}
        {{ form.as_p }}
        <button name="submit">Add project</button>
    </form>
    <!-- <a href="{% url 'todo_lists:new_project' project.id %}">Add a new project:</a>
 -->
{% endblock content %}

projects.html

<!doctype html>
{% extends "todo_lists/base.html" %}

{% block content %}

    <p>Projects</p>
    <a href="{% url 'todo_lists:new_project' %}">Add new project</a>
    <ul>
        {% for project in projects %}
            <li>
                <a href="{% url 'todo_lists:project' project.id %}">{{ project.id }}</a>
                <!-- <a href="{% url 'todo_lists:project' project.id %}">{{ project }}</a> -->
                <p>Name: {{ project.name }}</p>
                <p>Due date: {{ project.due_date }}</p>
                <p>project_code: {{ project.project_code }}</p>
                <p>details: {{ project.details }}</p>
                <p>team: {{ project.team }}</p>
            </li>
        {% empty %}
            <li>No project has been added yet.</li>
        {% endfor %}
    </ul>

    {% endblock content %}

Answer 1

谢谢 Marcel h 和 BrianD，我找到了答案，原来是评论导致了问题，即使我已经把它作为评论，它仍然导致了问题，我的解决方案是删除该评论。

Answer 2

html 评论中的模板标签仍由模板引擎呈现。演示：

from django import template

t = template.Template("""
<!-- {% url 'test' %} -->
""")

t.render(template.Context())

这将 return:

NoReverseMatch: Reverse for 'test' not found. 'test' is not a valid view function or pattern name.

即使模板标签 url 包含在 html 注释中，如果没有名为 test 的 url，它仍然会引发错误。

反向 'new_project'，未找到参数 '('',)'。尝试了 1 种模式：['new_project/$']

Reverse for 'new_project' with arguments '('',)' not found. 1 pattern(s) tried: ['new_project/$']

python

django

django-views

django-templates

django-urls