title: How to set a background image in tkinter using grid only
body: <p>I'm trying to set a background image to my tkinter window, however I don't quite know how to resize it so it fits the dimensions of the window. I've looked online, and all the tutorials/answers use pack (to expand and fill), but I can't use pack because I have a bunch of other buttons/labels that all use grid (this is a minimal workable example, my actual script is much bigger with more buttons/larger size). Is there any way to do this using grid?</p>
  
  <p>This is my current setup:</p>
  
  <pre><code>import tkinter as tk
  from PIL import ImageTk, Image
  
  root = tk.Tk()
  background_image = ImageTk.PhotoImage(Image.open("pretty.jpg"))
  l=tk.Label(image=background_image)
  l.grid()
  
  tk.Label(root, text="Some File").grid(row=0)
  e1 = tk.Entry(root)
  e1.grid(row=0, column=1)
  
  
  tk.mainloop()
  </code></pre>