While counting up instead of down does allow the use of &quot;i &gt;= arraylength&quot; construct to check whether an item was found, it&#x27;s still not as clear as using an explicit &quot;found&quot; boolean.  Once you do that, it doesn&#x27;t matter whether you count up or down.  Also, Python&#x27;s for...else construct is nice for this sort of thing.<p>Fun fact: I usually count down unless there&#x27;s a code-specific reason to count up.  It&#x27;s one of the biggest &quot;tells&quot; that I wrote a piece of code, and it exists because I&#x27;m old enough to have worked with compilers stupid enough that they really did produce more efficient code that way.  Nowadays I wouldn&#x27;t generally recommend it, because AFAIK nobody has made a production-level compiler that dumb for quite a while.