title: Python 3.3: Recursive version of a function
body: <pre><code>def abc(s):
      filter = [i for i in s.lower() if i in 'abcdefghijklmnopqrstuvwxyz']
      for i in range(len(filter) - 1):
          if filter[i] &gt; filter[i+1]:
              return print(s, "is not abcdearian")
      return print(s,  "is abcdearian")
  
  
  while True:
      try:
          s = input("String? ")
  abc(s)
  </code></pre>
  
  <p>I'am having trouble making a recursive version of abc(s). Any ideas?</p>