title: How to check that an input is a decimal?
body: <p>I would like an input to keep asking for an input unless the input is a number with two or less decimals.</p>
  
  <pre><code>number = input('please enter a number')  
  while number **is not a decimal (insert code)**:  
  . . . .number = input('incorrect input,\nplease enter a number')
  </code></pre>