title: How to loop through a column in Python?
body: <p>I <strong>have</strong> seen answers about this question but no one helped me. Some used <em>numpy</em>, and some people answered using other platforms that help Python to be simpler. I don't want these type of things, I want with the simple Python without importing libraries or anything more.</p>
  
  <p>Let's say: I would want to do a method that checks if there's at least one column in the 2D array that the column has the same values.
  For example:</p>
  
  <pre><code>arr = [[2,0,3],[4,2,3],[1,0,3]]
  </code></pre>
  
  <p>Sending <code>arr</code> to my method would return <code>True</code> because in the third column there is in each term the number 3.</p>
  
  <p>How would I write this method? How do I loop through each column in the 2D array?</p>