title: python, shapely: How to determine if two polygons cross each other, while allowing their edges to overlap
body: <p>I'm trying to find out whether two polygons cross each other. By 'cross' I mean their exteriors are allowed to touch each other, but their interior cannot:</p>
  
  <p>Only the two <strong>rightmost</strong> solutions below are allowed:</p>
  
  <p><a href="https://i.stack.imgur.com/leEre.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/leEre.png" alt="enter image description here"></a></p>
  
  <p>I've tried using shapely intersects or crosses (and some others) but couldn’t find a built-in function that works (they usually relate to both interior and exterior).</p>