title: python list of lists to dict when key appear many times
body: <p>I know to write something simple and slow with loop, but I need it to run super fast in big scale.</p>
  <p>input:</p>
  <pre><code>lst = [[1, 1, 2], [&quot;txt1&quot;, &quot;txt2&quot;, &quot;txt3&quot;]]
  </code></pre>
  <p>desired out put:</p>
  <pre><code>d = {1 : [&quot;txt1&quot;, &quot;txt2&quot;], 2 : &quot;txt3&quot;]
  </code></pre>
  <p>There is something built-in at python which make <code>dict()</code> extend key instead replacing it?</p>
  <pre><code>dict(list(zip(lst[0], lst[1])))
  </code></pre>