【发布时间】：2021-05-18 00:48:27
【问题描述】：
我正在尝试创建一个 url-shohrtener，但它给了我这个错误：
django.urls.exceptions.NoReverseMatch：找不到“”的反向。 '' 不是有效的视图函数或模式名称。
from django.contrib import admin
from django.urls import path, include
urlpatterns = [
path('admin/', admin.site.urls),
path('', include('shorturl.urls')),
]
这是我的应用程序 urls.py：
from django.urls import path
from . import views
urlpatterns = [
path('', views.index, name='index'),
path('<str:id>/', views.redirect_url, name='redirect'),
]
这些是views.py：
from django.shortcuts import render, redirect
from .models import Url
import random
import string
def redirect_url(request, id):
urls = Url.objects.filter(short=id)
link = ""
for i in urls:
link = i.url
return redirect(link)
def index(request):
if request.method == "POST":
link = request.POST.get("link")
short = ""
if Url.objects.filter(url=link).exists():
urls = Url.objects.all()
for i in urls:
if i.url == link:
short = i.short
break
else:
short = get_short_code()
url = Url(url=link, short=short)
url.save()
new_url = request.get_host() + "/" + short
return render(request, 'shorturl/index.html', {"new_url":new_url})
return render(request, 'shorturl/index.html')
def get_short_code():
length = 6
char = string.ascii_uppercase + string.digits + string.ascii_lowercase
while True:
short_id = ''.join(random.choice(char) for x in range(length))
if Url.objects.filter(short=short_id).exists():
continue
else:
return short_id
以防万一这是模板很重要：
<!doctype html>
<html lang="en">
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- Bootstrap CSS -->
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta1/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-giJF6kkoqNQ00vy+HMDP7azOuL0xtbfIcaT9wjKHr8RbDVddVHyTfAAsrekwKmP1" crossorigin="anonymous">
<title>Shroten URL</title>
<script>
function myFunction() {
/* Get the text field */
var copyText = document.getElementById("myInput");
/* Select the text field */
copyText.select();
copyText.setSelectionRange(0, 99999); /* For mobile devices */
/* Copy the text inside the text field */
document.execCommand("copy");
}
</script>
</head>
<body>
<div class="container" style="padding-top: 5%;">
<form method="POST">
{% csrf_token %}
<div class="mb-3">
<label for="exampleInputEmail1" class="form-label">Link</label>
<input name="link" type="text" class="form-control" id="exampleInputEmail1" aria-describedby="emailHelp">
</div>
<button type="submit" class="btn btn-primary">Shorten</button>
</form>
{% if new_url %}
<div class="mb-3">
<label for="exampleInputEmail1" class="form-label">Short Link</label>
<input name="link" type="text" value= {{new_url}} class="form-control" id="myInput" aria-describedby="emailHelp">
</div>
<button onclick="myFunction()" class="btn btn-primary">COPY</button>
{% endif %}
</div>
<!-- Optional JavaScript; choose one of the two! -->
<!-- Option 1: Bootstrap Bundle with Popper -->
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta1/dist/js/bootstrap.bundle.min.js" integrity="sha384-ygbV9kiqUc6oa4msXn9868pTtWMgiQaeYH7/t7LECLbyPA2x65Kgf80OJFdroafW" crossorigin="anonymous"></script>
<!-- Option 2: Separate Popper and Bootstrap JS -->
<!--
<script src="https://cdn.jsdelivr.net/npm/@popperjs/core@2.5.4/dist/umd/popper.min.js" integrity="sha384-q2kxQ16AaE6UbzuKqyBE9/u/KzioAlnx2maXQHiDX9d4/zp8Ok3f+M7DPm+Ib6IU" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta1/dist/js/bootstrap.min.js" integrity="sha384-pQQkAEnwaBkjpqZ8RU1fF1AKtTcHJwFl3pblpTlHXybJjHpMYo79HY3hIi4NKxyj" crossorigin="anonymous"></script>
-->
</body>
</html>
我在终端上得到的错误网站工作正常。 整个错误是：
Traceback (most recent call last):
File
"C:\Users\Dell\Desktop\new\xp\lib\site-packages\django\core\handlers\exception.py",
line 47, in inner
response = get_response(request) File "C:\Users\Dell\Desktop\new\xp\lib\site-packages\django\core\handlers\base.py",
line 181, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs) File "C:\Users\Dell\Desktop\new\xp\Url-shortener\shorturl\views.py", line
12, in redirect_url
return redirect(link) File "C:\Users\Dell\Desktop\new\xp\lib\site-packages\django\shortcuts.py",
line 41, in redirect
return redirect_class(resolve_url(to, *args, **kwargs)) File "C:\Users\Dell\Desktop\new\xp\lib\site-packages\django\shortcuts.py",
line 131, in resolve_url
return reverse(to, args=args, kwargs=kwargs) File "C:\Users\Dell\Desktop\new\xp\lib\site-packages\django\urls\base.py",
line 87, in reverse
return iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs)) File "C:\Users\Dell\Desktop\new\xp\lib\site-packages\django\urls\resolvers.py",
line 685, in _reverse_with_prefix
raise NoReverseMatch(msg) django.urls.exceptions.NoReverseMatch: Reverse for '' not found. '' is not a valid view function or pattern
name.
请帮我解决这个问题。
【问题讨论】：
-
urls = Url.objects.filter(short=id)不应该是urls = Url.objects.get(short=id)吗？即 short 应该是唯一的。对于 short pass 的值，可能不存在这样的实例。请改用get_object_or_404(Url, short=id)。如果不存在这样的模型实例，它将简单地给出 404。 -
我们可以通过两种方式做到这一点。filter() 给出了一个查询集，所以我使用了一个 for 循环来获取短变量
-
.filter()给出了一个查询集，但在您的用例中，short是唯一的，您只需要一个结果。当你可以简单地得到你想要的结果时，为什么要无缘无故地循环呢？ （如果您的模型中没有短字段，也可以输入unique=True）此外，使用.get()的好处是它假设只会出现一个结果。如果你得到多个或没有，它会引发异常。当然，过滤器对此没有任何问题。 -
谢谢我会改变它...
标签： python python-3.x django