c</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">valid_count</span> <span class="o">/</span> <span class="nb">len</span><span class="p">(</span><span class="n">match_dis</span><span class="p">))</span>
        <span class="n">valid_count</span> <span class="o">=</span> <span class="nb">sum</span><span class="p">(</span><span class="n">x</span> <span class="o">&gt;</span> <span class="n">thres</span> <span class="k">for</span> <span class="n">x</span> <span