title: Python TypeError: unsupported operand type(s) for /: 'str' and 'float'
body: <p>My code:</p>
  
  <pre><code>total=tef+tpf-price
  </code></pre>
  
  <p>I've got this error:</p>
  
  <pre><code>  total=tef+tpf-price
  unsupported operand type(s) for -: 'float' and 'str'
  </code></pre>
  
  <p>How do I fix it?</p>