title: Python 'list indices must be integers, not tuple" error
body: <p>I'm working on moving a robot around a 2d grid room of 8 x 8, and one part is initialising the sensors which consist of the closest 5 tiles around the robot.</p>
  
  <pre><code>self.sensors = [0 for x in xrange(5)]
  </code></pre>
  
  <p>here I'm creating an empty of array of 5 elements.</p>
  
  <p>but when I attempt to set the value of sensors like this:</p>
  
  <pre><code>    if self.heading == 'East':
          self.sensors[0] = self.room[self.x, self.y-1]
          self.sensors[1] = self.room[self.x+1, self.y-1]
          self.sensors[2] = self.room[self.x+1, self.y]
          self.sensors[3] = self.room[self.x+1, self.y+1]
          self.sensors[4] = self.room[self.x, self.y+1]
  </code></pre>
  
  <p>I get the error of 'list indices must be integers, not tuples'.</p>