title: Column selection with mouse drag using Python/Tkinter Text function
body: <p>I am developing a specialized text editor for a company. I am developing in Python 3.7.4 and I'm using Tkinter. One of the features I would like to develop is to select a range of columns/rows by dragging the mouse pointer from a starting point. If you're familiar with Notepad++, it is equivalent to their Alt + mouse drag feature. I've included a short video demonstrating this feature in Notepad++. <a href="https://www.youtube.com/watch?v=BEDURCPTrHo&amp;feature=youtu.be" rel="nofollow noreferrer">https://www.youtube.com/watch?v=BEDURCPTrHo&amp;feature=youtu.be</a></p>
  
  <p>I have not found a similar keystroke combination in Tkinter that allows this within a Text box. I am familiar with most elements of the Text method, and know how to determine row/column index, selection range, insert/delete, bbox attributes, etc. And I also know how to bind mouse events (click, move, release). And finally I am aware of the notion of monospace fonts and calculating row/column for the mouse event x/y coordinates. I'm just wondering if anybody has written any code to do this, or knows of a Tkinter Text method feature that I may be overlooking.  </p>
  
  <p>Thanks in advance for your help.</p>