Truthiness values are also WTF worthy (although not mentioned above).<p><pre><code>    if not x:
        do_something()
</code></pre>
Where do_something will occur if x is None, zero, 0.0, a blank string or even <i>midnight</i> in some versions of python.<p>This has bitten me multiple times. It&#x27;s a violation of python&#x27;s explicit over implicit. It&#x27;s an example of weak typing in an otherwise strongly typed language. There&#x27;s really no good reason for it.<p>IMO, if x isn&#x27;t a boolean, that line should just throw an exception. If you want to check for x being 0.0 or &quot;&quot;, you should do x == &quot;&quot; or x == 0.0.