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<section id="subclassing-flask">
<h1>Subclassing Flask<a class="headerlink" href="#subclassing-flask" title="Link to this heading"></a></h1>
<p>The <a class="reference internal" href="../api.html#flask.Flask" title="flask.Flask"><code class="xref py py-class docutils literal notranslate"><span class="pre">Flask</span></code></a> class is designed for subclassing.</p>
<p>For example, you may want to override how request parameters are handled to preserve their order:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span><span class="w"> </span><span class="nn">flask</span><span class="w"> </span><span class="kn">import</span> <span class="n">Flask</span><span class="p">,</span> <span class="n">Request</span>
<span class="kn">from</span><span class="w"> </span><span class="nn">werkzeug.datastructures</span><span class="w"> </span><span class="kn">import</span> <span class="n">ImmutableOrderedMultiDict</span>
<span class="k">class</span><span class="w"> </span><span class="nc">MyRequest</span><span class="p">(</span><span class="n">Request</span><span class="p">):</span>
<span class="w"> </span><span class="sd">&quot;&quot;&quot;Request subclass to override request parameter storage&quot;&quot;&quot;</span>
<span class="n">parameter_storage_class</span> <span class="o">=</span> <span class="n">ImmutableOrderedMultiDict</span>
<span class="k">class</span><span class="w"> </span><span class="nc">MyFlask</span><span class="p">(</span><span class="n">Flask</span><span class="p">):</span>
<span class="w"> </span><span class="sd">&quot;&quot;&quot;Flask subclass using the custom request class&quot;&quot;&quot;</span>
<span class="n">request_class</span> <span class="o">=</span> <span class="n">MyRequest</span>
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<p>This is the recommended approach for overriding or augmenting Flasks internal functionality.</p>
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