小编Dan*_*ues的帖子

假设我有一个 base.html 模板。在 base.html 模板中包含菜单栏、固定页脚和内容块。例子：

基本文件

<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
    <a class="navbar-brand mr-0 mr-md-2" href="/">
            <img src="{{ url of an image added in the database that can be changed by the user }}" height="60" class="d-inline-block" alt="site">Site</a>
        <button class="btn btn-link bd-search-docs-toggle d-md-none p-0 ml-3" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNav">
    <ul class="navbar-nav">
    <li class="nav-item">
        <a class="nav-link" href="#">Diário Oficial do PL</a>
    </li>
    <li class="nav-item">
        <a class="nav-link" href="#">Site Oficial do PL</a>
    </li>
    <li>
        <a …

我对该len()函数如何在python3内部工作（如何实现）感兴趣。

有人可以帮我吗？