title: Python- how do I use re to match a whole string
body: <p>I am validating the text input by a user so that it will only accept letters but not numbers. so far my code works fine when I type in a number (e.g. 56), it warns me that I should only type letters and when I type in letters it doesn't return anything (like it should do). My problem is that it accepts it when I start by typing letters followed by numbers e.g. (s45). what it does is accept the first letter but not the whole string. I need it to accept the whole string.</p>
  
  <pre><code>def letterCheck(aString):
      if len(aString) &gt; 0:
          if re.match("[a-zA-Z]", aString) != None:
              return ""
      return "Enter letters only"
  </code></pre>