title: What is %timeit in Python?
body: <p>I always read the code to calculate the time like this way:</p>
  <pre><code>%timeit function()
  </code></pre>
  <p>What does &quot;%&quot; mean here?</p>
  <p>I think, the &quot;%&quot; is always used to replace something in a string, like %s means replace a string, %d replace a data, but I have no idea about this case.</p>