title: Python Tkinter canvas.xview units
body: <p>How are the 'units' (<code>what</code>) from the Tkinter canvas scrolling methods <code>xview(SCROLL, step, what)</code> and <code>yview(SCROLL, step, what)</code> defined? Is it defined in pixels? Is it possible to change it (for a slower scrolling for example)?</p>
  
  <p>For a better context please see the code <a href="https://stackoverflow.com/questions/6495317/python-tkinter-canvas-scrolling-with-mouse-position">here</a>.</p>
  
  <p>Thanks in advance.</p>