title: comparison of negative numbers turn out wrong
body: <p>I am doing a test of position bounding boxes, but when comparing negative (south or west) positions with other negative positions it turns the result upside down.</p>
  
  <pre><code>if minlat &gt; maxlat:
      minlat, maxlat = swap(minlat, maxlat)
  if minlon &gt; maxlon:
      minlon, maxlon = swap(minlon, maxlon)
  </code></pre>
  
  <p>This works fine when comparing latitudes on northern hemisphere or positions on southern with northern hemisphere, but when comparing positions on southern hemisphere it turns them around (i.e., -20.4 is less than -20.8). Is there a simple solution to this, or must I make a different test if both values are less than 0?</p>