input: Write a python function to create a tkinter GUI with a dropdown menu to select Python versions and a button to print the selected version.
  assert language_var.get() == 'Python 2.7'
  assert language_var.get() == 'Python 3.4'
  assert language_var.get() == 'Python 3.6'
  assert language_var.get() == 'Python 3.7'
output: def create_python_version_selector():
      import tkinter as tk
      from tkinter import ttk
  
      def print_selected_version():
          print(language_var.get())
  
      root = tk.Tk()
      root.title("Python Version Selector")
  
      language_var = tk.StringVar()
      language_var.set("Python 2.7")
  
      versions = ["Python 2.7", "Python 3.4", "Python 3.6", "Python 3.7"]
  
      dropdown = ttk.OptionMenu(root, language_var, versions[0], *versions)
      dropdown.pack(pady=20)
  
      button = tk.Button(root, text="Print Version", command=print_selected_version)
      button.pack(pady=20)
  
      root.mainloop()
  
  create_python_version_selector()