title: Can't get an Entry object which is a fraction
body: <pre><code>import tkinter as tk
  import fractions
  
  def tests(parameters, root):
      print(parameters[0])
      root.destroy()
      return None
  
  class ScrolledFrame(tk.Frame):
  
      def __init__(self, parent, vertical=True, horizontal=False):
          super().__init__(parent)
  
          # canvas for inner frame
          self._canvas = tk.Canvas(self)
          self._canvas.grid(row=0, column=0, sticky='news') # changed
  
          # create right scrollbar and connect to canvas Y
          self._vertical_bar = tk.Scrollbar(self, orient='vertical', command=self._canvas.yview)
          if vertical:
              self._vertical_bar.grid(row=0, column=1, sticky='ns')
          self._canvas.configure(yscrollcommand=self._vertical_bar.set)
  
          # create bottom scrollbar and connect to canvas X
          self._horizontal_bar = tk.Scrollbar(self, orient='horizontal', command=self._canvas.xview)
          if horizontal:
              self._horizontal_bar.grid(row=1, column=0, sticky='we')
          self._canvas.configure(xscrollcommand=self._horizontal_bar.set)
  
          # inner frame for widgets
          self.inner = tk.Frame(self._canvas)
          self._window = self._canvas.create_window((0, 0), window=self.inner, anchor='nw')
  
          # autoresize inner frame
          self.columnconfigure(0, weight=1) # changed
          self.rowconfigure(0, weight=1) # changed
  
          # resize when configure changed
          self.inner.bind('&lt;Configure&gt;', self.resize)
  
          # resize inner frame to canvas size
          self.resize_width = False
          self.resize_height = False
          self._canvas.bind('&lt;Configure&gt;', self.inner_resize)
  
      def resize(self, event=None): 
          self._canvas.configure(scrollregion=self._canvas.bbox('all'))
  
      def inner_resize(self, event):
          # resize inner frame to canvas size
          if self.resize_width:
              self._canvas.itemconfig(self._window, width=event.width)
          if self.resize_height:
              self._canvas.itemconfig(self._window, height=event.height)
  
  
  def interface(root):
      global parameters
      # create scrolled frame
      sf = ScrolledFrame(root, True, True)
      sf.pack(fill='both', expand=True) # resize with window
  
      entries= []
  
      tk.Label(sf.inner, text="a").grid(row=2, sticky='w')
      entry=tk.Entry(sf.inner)
      entries.append(entry)
      entry.grid(row=2, column=1)
  
      tk.Label(sf.inner, text="b").grid(row=3, sticky='w')
      entry=tk.Entry(sf.inner)
      entries.append(entry)
      entry.grid(row=3, column=1)
  
      def get():
          parameters=[]
          temp=[]
          temp.append(float(entries[0].get()))
          temp.append(round(float(fractions.Fraction(entries[1].get())), 7))
          parameters=temp
  
      bouton_Valider =tk.Button(sf.inner, text="Valider les paramètres", fg="blue", command=get)
      bouton_Valider.grid(row=4, column=1)
  
      bouton_Executer = tk.Button(sf.inner, text="Exécuter le programme", fg="red", command=lambda: tests(parameters, root))
      bouton_Executer.grid(row=5, column=1)
  
      root.mainloop() 
  
      return parameters
  </code></pre>
  
  <p>For the Entry 'b' , I want the user to enter a fraction like '4000/(60*60*1000)'. I tried to get this entry with the instruction:"round(float(fractions.Fraction(entries[1].get())), 7)", but after entering the values 'a' and 'b', and clicking on the "Valider les paramètres" button, I get the error:"ValueError: Invalid literal for Fraction: '4000/(60*10*100)' ". As a result of this, when I click the "Exécuter le programme" button, I get the error:"name 'parameters' is not defined"</p>