title: What are Canvas units specified in for Tkinter?
body: <p>I realize this is a trivial question, but I'm confused nonetheless. </p>
  
  <p>I have a 13 inch MacBook Pro with retina display. My system claims a 2560-by-1600 resolution in System Report. I assumed that the Canvas command in tkinter measured height and width in pixels, and the <a href="http://www.tkdocs.com/tutorial/canvas.html" rel="nofollow noreferrer">tk documentation</a> seem to indicate this too. Yet the following code, where I use 1200 as the width and 700 as the the height of a tkinter canvas, produces a canvas that mostly fills my screen. </p>
  
  <p>What units are the canvas height and width in?</p>
  
  <pre><code>from tkinter import *
  
  master = Tk()
  
  x = 1200
  y = 700
  
  w = Canvas(master, width=x, height=y)
  w.pack()
  
  
  mainloop()
  </code></pre>