title: How can I make this Python code more efficient
body: <p>I would greatly appreciate your feedback on my first ever Python project! :D</p>
  
  <p>Basically I am coding a Caesar Cipher and I think its pretty terribly 'optimised / efficient' if you know what I mean, this is because I copied and pasted the encrypt() method for the decrypt() method and the only thing I changes was instead of rotating the numbers more, I rotated them less. This is what I'm talking about:</p>
  
  <pre><code>       newPosition = (abc.find(letter) - key) % 26
  
  ^^ Instead of having a + (plus) I made it a - (minus) ^^
  </code></pre>
  
  <p>Is there a way I can sort of call the encrypt() method at just the newPosition line? Or what I did was correct and it doesn't need fixing (which I highly doubt)</p>
  
  <p>** Please do take in mind that I do not have much knowledge in Python (if any at all) since I just started today so don't blow my brain up with some super complex code. THANK YOU!!! **</p>
  
  <pre><code>abc = 'abcdefghijklmnopqrstuvwxyz'
  
  def main():
      message = input("Would you like to encrypt or decrypt a word?")
      if message.lower() == "encrypt":
          encrypt()
      elif message.lower() == "decrypt":
          decrypt()
      else:
          print("You must enter either 'encrypt' or 'decrypt'.")
          main()
  
  
  def encrypt():
      message = input("Enter a message to encrypt: ")
      message = message.lower()
      key = int(input("What number would you like for your key value?"))
      cipherText = ""
      for letter in message:
          if letter in abc:
              newPosition = (abc.find(letter) + key) % 26
              cipherText += abc[newPosition]
          else:
              cipherText += letter
      print(cipherText)
      return cipherText
  
  def decrypt():
      message = input("Enter a message to decrypt: ")
      message = message.lower()
      key = int(input("What number would you like for your key value?"))
      cipherText = ""
      for letter in message:
          if letter in abc:
              newPosition = (abc.find(letter) - key) % 26
              cipherText += abc[newPosition]
          else:
              cipherText += letter
      print(cipherText)
      return cipherText
  
  main()
  </code></pre>