title: python's counterpart for Ruby String#succ?
body: <p>I was wondering if there is a function (or method) in python that increments strings as in Ruby's <a href="http://ruby-doc.org/core-2.0.0/String.html#method-i-succ" rel="nofollow" title="String#succ">String#succ</a> method, ie:</p>
  
  <pre><code>~ $ irb --simple-prompt
  &gt;&gt; '2'.succ
  =&gt; "3"
  &gt;&gt; '99'.succ
  =&gt; "100"
  &gt;&gt; 'zzz'.succ
  =&gt; "aaaa"
  &gt;&gt;
  </code></pre>