title: Finding the minimum and maximum of a list of arrays
body: <p>Let's say I have 2 arrays inside a single array, like:</p>
  
  <pre><code>main_array = [[1, 2, 3, 4], [4, 5, 6, 7]]
  </code></pre>
  
  <p>I would like to find the <code>min</code> and <code>max</code> of each of those arrays and store them in a single array. For the above it would be:</p>
  
  <pre><code>result = [1, 4, 4, 7]
  </code></pre>
  
  <p>How do I use Python's inbuilt <code>min()</code> and <code>max()</code> in this case? </p>
  
  <p>I tried <code>min(main_array)</code> and <code>max(main_array)</code> but that is giving me:</p>
  
  <pre><code>result = [1,7]
  </code></pre>