找不到带有参数'（）'和关键字参数'{u'cd'：''}''的'course_detail'。尝试了1种模式：['courses /（？P <cd> \\\\ d +）/ $']

Question

I am fairly new to Django and I followed a tutorial which helped create a blog using Django. 我对Django相当陌生，我遵循了一个使用Django帮助创建博客的教程。 That project went fine. 那项目进展顺利。 But when I wanted to use what I learnt form that tutorial and make my own simple website that's when things went pear shaped. 但是，当我想使用从该教程中学到的知识并制作自己的简单网站时，事情就开始变样了。 I have been at this problem for a long time now and it is really bugging me, so I hoped a fresh pair of eyes could help me decode the issue. 我已经在这个问题上待了很长时间了，这确实使我烦恼，所以我希望能有一对新的眼睛可以帮助我解释这个问题。

The error I am getting is this: 我得到的错误是这样的：

Reverse for 'course_detail' with arguments '()' and keyword arguments '{u'cd': ''}' not found. 1 pattern(s) tried: ['course/(?P<cd>\\d+)/$']

Now I know that in my original project I never had a "u'" before the 'cd' in my arguments and I have no idea where this is coming from, I have looked tirelessly for what is causing this and I can't find it. 现在我知道在我的原始项目中，我的论点中的“ cd”之前从来没有“ u”，而且我也不知道这是从哪里来的，我一直在不懈地寻找导致它的原因，而我找不到它。

Here is the rest of the code regarding this issue: 以下是有关此问题的其余代码：

course_list.html course_list.html

   {% load staticfiles %}
    <html>
        <head>
            <title>Courses</title>
            <link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
            <link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap-theme.min.css">
            <link rel="stylesheet" href="{% static 'css/website.css' %}">
            <link href="//fonts.googleapis.com/css?family=Lobster&subset=latin,latin-ext" rel="stylesheet" type="text/css">
            <link href="https://fonts.googleapis.com/css?family=Oswald" rel="stylesheet" type="text/css">
        </head>
        <body>
            <div class="links">
                <h1><a href="">Home</a> |
                <a href="">Courses</a> |
                <a href="">Venues</a> |
                <a href="">About Us</a> |
                <a href="">Contact Us</a></h1>
            </div>

            <div class="page-header">
                <h1><a href="">Courses</a></h1>
            </div>

            <div class="content container">
                <div class="row">
                    <div class="col-md-8">
                    {% for course in courses %}
                        <div class="course">
                            <h2><a href="{% url 'course_detail' cd=course.cd %}">{{ course.course_name }}</a></h2>
                            <p><b>Course code: </b> {{ course.course_code }}</p>
                            <p><b>Price: </b> {{ course.price }} </p>
                            <p><b>Course topic: </b> {{ course.topic_details }} </p>
                                <div class="date">
                                    <p><b>Start Date: </b> {{ course.start_date }}</p>
                                    <p><b>End Date: </b> {{ course.end_date }}</p>
                                </div>
                            <p><b>Availability: </b> {{ course.status }}</p>
                            <p><b>Course venue: </b> {{ course.venue }}</p>
                            <p><b>Room course will be held in: </b> {{ course.room }}</p>

                                <button class="button">Book Course</button>

                        </div>
                    {% endfor %}
                    </div>
                </div>
            </div>
            <div class="footer">
                <h3>Other Links</h3>
            </div>

        </body>

    </html>

course_detail.html course_detail.html

 {% extends 'website/base.html' %}
    {% block content %}
                        <div class="course">
                            <p><b>Course code: </b> {{ course.course_code }}</p>
                            <p><b>Price: </b> {{ course.price }} </p>
                            <p><b>Course topic: </b> {{ course.topic_details }} </p>
                                <div class="date">
                                    <p><b>Start Date: </b> {{ course.start_date }}</p>
                                    <p><b>End Date: </b> {{ course.end_date }}</p>
                                </div>
                            <p><b>Availability: </b> {{ course.status }}</p>
                            <p><b>Course venue: </b> {{ course.venue }}</p>
                            <p><b>Room course will be held in: </b> {{ course.room }}</p>

                                <button class="button">Book Course</button>

                        </div>

    {% endblock %}

views.py views.py

from django.shortcuts import render
from django.shortcuts import render, get_object_or_404
from .models import Course

# Create your views here.
def course_list(request):
    courses = Course.objects.all()
    return render(request, 'website/course_list.html', {'courses': courses})

def course_detail(request, cd):
    course = get_object_or_404(Course, cd=cd)
    return render(request, 'website/course_detail.html', {'course': course})

urls.py urls.py

from django.conf.urls import url
from . import views

urlpatterns = [
    url(r'^$', views.course_list, name='course_list'),
    url(r'^course/(?P<cd>\d+)/$', views.course_detail, name='course_detail'),
]

Full trace 全迹

Request Method: GET
Request URL:    https://yr4-group-project-mfblack.c9users.io/
Django Version: 1.9
Exception Type: NoReverseMatch
Exception Value:    
Reverse for 'course_detail' with arguments '()' and keyword arguments '{u'cd': ''}' not found. 1 pattern(s) tried: ['course/(?P<cd>\\d+)/$']
Exception Location: /usr/local/lib/python2.7/dist-packages/django/core/urlresolvers.py in _reverse_with_prefix, line 508
Python Executable:  /usr/bin/python
Python Version: 2.7.6
Python Path:    
['/home/ubuntu/workspace',
 '/usr/lib/python2.7',
 '/usr/lib/python2.7/plat-x86_64-linux-gnu',
 '/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/PILcompat',
 '/usr/lib/python2.7/dist-packages/gtk-2.0',
 '/usr/lib/pymodules/python2.7']
Server time:    Tue, 25 Oct 2016 16:08:46 +0000

Hopefully someone can help as I have tried all the things I can think of to get it working. 希望有人可以帮忙，因为我尝试了所有我认为可以使它正常工作的事情。 If there is need of any more code then please let me know. 如果需要更多代码，请告诉我。

UPDATE: models.py 更新： models.py

class Course(models.Model):
    MY_CHOICES = (
        ('Open', 'Open'),
        ('Closed', 'Closed'),
        ('Fully Booked', 'Fully Booked'),
    )
    course_name = models.CharField(max_length=40)
    course_code = models.CharField(max_length=40)
    price = models.CharField(max_length=40, default='add price')
    topic_details = models.TextField(max_length=200)
    start_date = models.DateField('start date')
    end_date = models.DateField('end date')
    status = models.CharField(max_length=20, choices=MY_CHOICES)
    venue = models.ForeignKey(Venue, on_delete=models.CASCADE)
    room = models.CharField(max_length=20)
    def __str__(self):
        return self.course_name

I tried your answer and it worked, I am getting the website loading now but now that I click on the a course name I get this error: 我尝试了您的答案，它起作用了，现在我正在加载网站，但是现在单击课程名称，会出现此错误：

FieldError at /course/1/
Cannot resolve keyword 'cd' into field. Choices are: course_code, course_name, end_date, id, price, room, start_date, status, student, topic_details, venue, venue_id
Request Method: GET
Request URL:    https://yr4-group-project-mfblack.c9users.io/course/1/
Django Version: 1.9
Exception Type: FieldError
Exception Value:    
Cannot resolve keyword 'cd' into field. Choices are: course_code, course_name, end_date, id, price, room, start_date, status, student, topic_details, venue, venue_id
Exception Location: /usr/local/lib/python2.7/dist-packages/django/db/models/sql/query.py in names_to_path, line 1330
Python Executable:  /usr/bin/python
Python Version: 2.7.6
Python Path:    
['/home/ubuntu/workspace',
 '/usr/lib/python2.7',
 '/usr/lib/python2.7/plat-x86_64-linux-gnu',
 '/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/PILcompat',
 '/usr/lib/python2.7/dist-packages/gtk-2.0',
 '/usr/lib/pymodules/python2.7']
Server time:    Tue, 25 Oct 2016 17:14:37 +0000

Answer 1

The trace log is telling you that it cannot find a course_detail url with a blank captured group cd . 跟踪日志告诉您无法找到带有空白捕获组cd的course_detail URL。 (NB The u refers to unicode and has nothing to do with your issue.) （注意， u表示unicode，与您的问题无关。）

Your course_detail url expects one or more digits for cd : 您的course_detail网址应为cd一位或多位数字：

r'^course/(?P<cd>\d+)/$'

But it is passed...nothing! 但是它通过了……什么都没有！

'course_detail' with arguments '()' and keyword arguments '{u'cd': ''}'

Why? 为什么？ Because in your view, {% url 'course_detail' cd=course.cd %} , course.cd is blank. 因为您认为{% url 'course_detail' cd=course.cd %} ， course.cd为空。

I would need to see your Course model, but my suspicion is that you are simple using cd instead of the standard id . 我需要查看您的Course模型，但是我怀疑您使用cd而不是标准id很简单。 Try switching to course.id : that should fix the issue. 尝试切换到course.id ：应该可以解决此问题。

UPDATE: 更新：

Your second error is caused by the exact same issue in views.py : 您的第二个错误是由views.py完全相同的问题引起的：

get_object_or_404(Course, cd=cd)

cd here is undefined: you should change it to id . cd在这里是未定义的：您应该将其更改为id 。

找不到带有参数'（）'和关键字参数'{u'cd'：''}''的'course_detail'。尝试了1种模式：['courses /（？P <cd> \\\\ d +）/ $']

问题描述

1 个解决方案

解决方案1
0 已采纳 2016-10-25 16:41:37

找不到带有参数&#39;（）&#39;和关键字参数&#39;{u&#39;cd&#39;：&#39;&#39;}&#39;&#39;的&#39;course_detail&#39;。 尝试了1种模式：[&#39;courses /（？P <cd> \\\\ d +）/ $&#39;]

问题描述

1 个解决方案

解决方案1 0 已采纳 2016-10-25 16:41:37

找不到带有参数'（）'和关键字参数'{u'cd'：''}''的'course_detail'。尝试了1种模式：['courses /（？P <cd> \\\\ d +）/ $']

解决方案1
0 已采纳 2016-10-25 16:41:37