title: How to check if an element of a list is a number?
body: <p>How can I check if the first element of the list (below) is a number (using some sort of regular expression) in python:</p>
  
  <pre><code>temp = ['1', 'abc', 'XYZ', 'test', '1']
  </code></pre>
  
  <p>Many thanks.</p>