title: io.StringIO encoding in python3
body: <p>I can't seem to find what's the default encoding for <code>io.StringIO</code> in Python3. Is it the locale as with <code>stdio</code>?</p>
  
  <p>How can I change it?</p>
  
  <p>With <code>stdio</code>, seems that just reopening with correct encoding works, but there's no such thing as reopening a <code>StringIO</code>.</p>