title: Browse files to open and run using GUI python
body: <p>Hi i have some python scripts. I need to create a GUI with few buttons, to open those files by browsing. I have to run those scripts just by clicking the GUI button, and should write the output into a n excel sheet. I tried with the below code, but with that i can just read the file! please help?
  Thank you</p>
  
  <pre><code>from Tkinter import *            
  from tkFileDialog   
  import askopenfilename      
  
  def callback():
      r = open(askopenfilename(),'r')
  
  a = Button(text='click me', command=callback)
  a.pack()
  
  mainloop()
  </code></pre>