title: Code won't run when button is pressed
body: <p>So I have been working on my coursework and I am trying to encrypt a password. However, the code runs as soon as I start to initialise the program and won't run when I press the specified button. This is what I have so far:</p>
  
  <pre><code>import tkinter as tk
  from cryptography.fernet import Fernet
  
  #validate function
  def validateStylist(window):
      password = passwordEntry.get().encode("utf-8")
      cipher_text = cipher_suite.encrypt(password)
      plain_text = cipher_suite.decrypt(cipher_text)
      print(plain_text)
  
  key = Fernet.generate_key()
  cipher_suite = Fernet(key)
  
  MEDIUM_FONT = ("Berlin Sans FB", 12)
  LARGE_FONT = ("Berlin Sans FB", 16)
  
  window = tk.Tk()
  
  titleLabel = tk.Label(window, text="Register Stylist", font=LARGE_FONT, bg="#FFC0CB")
  titleLabel.grid(columnspan = 4)
  
  #Password
  passwordLabel = tk.Label(window, text="Password:", font=MEDIUM_FONT, bg="#FFC0CB")
  passwordLabel.grid(row=1,column=3)
  passwordVar = tk.StringVar(window)
  passwordEntry = tk.Entry(window, textvariable=passwordVar)
  passwordEntry.grid(row=2,column=3)
  
  finishButton = tk.Button(window, text="Finish",
                            command=validateStylist(window))
  finishButton.grid(row=4, column=3, sticky="ew")
  
  
  window.mainloop()
  </code></pre>