擅长:python、mysql、java
<h3>404错误的原因:</h3>
<p>当重定向到<code>/mainpage</code>时,Flask将在<code>login.py</code>文件中查找路由处理程序,而不是<code>mainpage.py</code>。因为<code>login.py</code>没有<code>/mainpage</code>的路由处理程序,所以它给您一个404。它永远不会到达<code>mainpage.py</code>。</p>
<h3>你想做什么和可能的解决方案:</h3>
<p>你要做的是在不同的文件之间分离路由。为此,您需要显式地<em>告诉</em>Flask路由处理程序在哪里(换句话说,它应该在哪些文件中查找路由处理程序)。</p>
<p>有两种方法:</p>
<ol>
<li><p>请参阅本文档(<a href="http://flask.pocoo.org/docs/0.12/patterns/packages/" rel="nofollow noreferrer">Larger Applications</a>)以了解如何将文件组织为包。您必须将mainpage.py导入login.py,反之亦然。</p></li>
<li><p>或者使用蓝图:<a href="http://flask.pocoo.org/docs/0.12/blueprints/#blueprints" rel="nofollow noreferrer">Modular Applications with Blueprints</a>。</p></li>
</ol>
<blockquote>
<p>Please note that you'll only need that if your application has a substantial size. If you have just a few route handlers, you should probably keep it simple with everything in one single file.</p>
</blockquote>