title: Issues using grid vs pack for ttk Progressbar
body: <p>I'm trying to create a progressbar class that combines the standard progress bar with a label showing the percent the bar is filled in. This value can then be updated to show percent completion. The class itself works fine, but there are two issues with trying to place both the widgets in the class and the class itself.</p>
  
  <p>When I use <code>pack(side = tk.LEFT)</code> the widgets pack correctly in the class. However, then when I use this class within my main program (which is managed by grid) the label vanishes.</p>
  
  <p>Secondly, using <code>grid()</code> with correct column spacing in my class stacks the two widgets on top of each other, not side by side as intended. When trying to use the class within my main program, I get the error:</p>
  
  <p><code>_tkinter.TclError: cannot use geometry manager pack inside . which already has slaves managed by grid</code></p>
  
  <p>Code here:</p>
  
  <pre><code>import tkinter as tk
  import tkinter.ttk as ttk
  
  class ProgressBarPercent(tk.Frame):
      def __init__(self, parent, orient, length, mode):
          tk.Frame.__init__(self, parent)
  
          self.progress = ttk.Progressbar(self, orient = orient, 
                length = length, mode = mode)
          self.text = tk.StringVar()
          self.text.set("0%")
          self.percent = tk.Label(textvariable = self.text)
          self.percent.grid(column=0, row=0)
          self.progress.grid(column=1, row=0)
  
      def value(self, value):
          self.progress['value'] = value
          percent_value = round(value, 1)
          self.text.set(str(percent_value) + '%')
  
  
  if __name__ == "__main__":
      root = tk.Tk()
  
      progress = ProgressBarPercent(root, orient = tk.HORIZONTAL, 
                    length = 100, mode = 'determinate') 
  
      progress.grid()
      progress.value(37.322)
  
      root.mainloop()
  </code></pre>