title: Python: Compare strings with 'or' operator
body: <p>In the Python3 tutorials, it is stated that "It is possible to assign the result of a comparison or other Boolean expression to a variable." The example given is:</p>
  
  <pre><code>&gt;&gt;&gt; string1, string2, string3 = '', 'Trondheim', 'Hammer Dance'
  &gt;&gt;&gt; non_null = string1 or string2 or string3
  &gt;&gt;&gt; non_null
  'Trondheim'
  </code></pre>
  
  <p>What exactly does the 'or' operator do when comparing strings? Why is 'Trondheim' chosen?</p>