title: Tkinter IntVar not working
body: <p>I have a mainframe class and then a 'inforow' class that fills info on the frame row by row but the StringVar and Intvar's dont seem to work. They are being set as the printout shows but the checkbutton doesn't reflect the value that they are being set to. I have made a simpler version that highlights the issue in these two files.</p>
  
  <p>I am using 'Python 2.7.12 (v2.7.12:d33e0cf91556, Jun 27 2016, 15:19:22) [MSC v.1500 32 bit (Intel)] on win32'</p>
  
  <p>When I run mainframe.py all the checkbuttons are blank but I am expecting them to be a mix of set and unset.</p>
  
  <p>mainframe.py</p>
  
  <pre><code>from Tkinter import *
  import ttk
  import inforow
  
  testinfo = {'ITEM 1': {'one':1, 'two':0, 'three':1}
      , 'ITEM 2': {'one':0, 'two':1, 'three':0}}
  
  class MainFrame(Frame):
  
      def __init__(self, parent=None, **options):
          Frame.__init__(self, parent, **options)
          self.pack(expand=YES, fill=BOTH)
          self.addHeader()
          self.addInfo(testinfo)
  
      def addHeader(self):
          Label(self, text="Item").grid(row=0,column=0)
          Label(self, text="one").grid(row=0,column=1)
          Label(self, text="two").grid(row=0,column=2)
          Label(self, text="three").grid(row=0,column=3)
  
      def addInfo(self, info):
          row = 1
          for item in info:
              inforow.InfoRow(self, row, item, info[item])
              row += 1
  
  if __name__ == "__main__": 
      root = Tk()
      MainFrame(root)
      root.mainloop()
  </code></pre>
  
  <p>and inforow.py</p>
  
  <pre><code>from Tkinter import *
  import ttk
  
  class InfoRow():
  
      def __init__(self, root, row, item, values):
          self.chkUsedVar1 = IntVar()
          self.chkUsedVar1.set(values["one"])
          self.chkUsedVar2 = IntVar()
          self.chkUsedVar2.set(values["two"])
          self.chkUsedVar3 = IntVar()
          self.chkUsedVar3.set(values["three"])
  
  
          self.skillLabel = Label(root, width=10, text=item, anchor="w")
          self.skillLabel.grid(row=row,column=0,sticky=W)
  
          self.usedChkButton1 = Checkbutton(root, text='Used1', variable=self.chkUsedVar1)
          self.usedChkButton1.grid(row=row,column=1)
  
          self.usedChkButton2 = Checkbutton(root, text='Used2', variable=self.chkUsedVar2)
          self.usedChkButton2.grid(row=row,column=2)
  
          self.usedChkButton3 = Checkbutton(root, text='Used3', variable=self.chkUsedVar3)
          self.usedChkButton3.grid(row=row,column=3)
          print 'Row ' + item
          print self.chkUsedVar1.get()
          print self.chkUsedVar2.get()
          print self.chkUsedVar3.get()
          print 
  </code></pre>