title: python size of byte string in bytes
body: <p>I'm confused as to why:</p>
  <pre class="lang-py prettyprint-override"><code>len(b'123') == 3
  import sys
  sys.getsizeof(b'123') == 36
  </code></pre>
  <p>What exactly is <code>b'123'</code>?</p>