title: Python function returns PY_VAR1 unexpectedly
body: <p>I am expecting my button function to print a number (<code>minutes_selected</code>) based on the current value of the Spinner UI element, but the variable is always PY_VAR1:</p>
  
  <pre><code>from tkinter import *
  from tkinter import ttk
  
  def get_minutes():
      global minutes_selected
      minutes_selected.get()
      print(mintes_selected)
  
  root = Tk()
  
  minutes_selected = StringVar()
  minutes_spinbox = Spinbox(root, from_ = 1, to = 1440, textvariable = minutes_selected).pack()
  </code></pre>
  
  <p>Is there some basic misunderstanding with regards to how variables can be access from within a function?</p>