title: Variable defined with with-statement available outside of with-block?
body: <p>Consider the following example:</p>
  
  <pre><code>with open('a.txt') as f:
      pass
  # Is f supposed to be defined here?
  </code></pre>
  
  <p>I have read the language docs (2.7) for with-statement as well as PEP-343, but as far as I can tell they don't say anything on this matter.</p>
  
  <p>In CPython 2.6.5 <code>f</code> does seem to be defined outside of the with-block, but I'd rather not rely on an implementation detail that could change.</p>