How to designate unreachable python code
<p>What's the pythonic way to designate unreachable code in python as in:</p>

<pre><code>gender = readFromDB(...) # either 'm' or 'f'
if gender == 'm':
    greeting = 'Mr.'
elif gender == 'f':
    greeting = 'Ms.'
else:
    # What should this line say?
</code></pre>
