title: Python while loop condition check for string
body: <p>In Codeacademy, I ran this simple python program:</p>
  
  <pre><code>choice = raw_input('Enjoying the course? (y/n)')
  
  while choice != 'y' or choice != 'Y' or choice != 'N' or choice != 'n':  # Fill in the condition (before the colon)
      choice = raw_input("Sorry, I didn't catch that. Enter again: ")
  </code></pre>
  
  <p>I entered y at the console but the loop never exited</p>
  
  <p>So I did it in a different way</p>
  
  <pre><code>choice = raw_input('Enjoying the course? (y/n)')
  
  while True:  # Fill in the condition (before the colon)
      if choice == 'y' or choice == 'Y' or choice == 'N' or choice == 'n':
          break
      choice = raw_input("Sorry, I didn't catch that. Enter again: ")
  </code></pre>
  
  <p>and this seems to work. No clue as to why</p>