Using a single letter (or short) variable name works well most of the time but has one problem: the variable can leak. It&#39;s easy to forget to write the del statement. Imagine a block statement that had the effect of deleting any variables initialized in the block. That is (using the with keyword in this example but there are other choices):<div><br></div><div>    x = foo()</div><div>    with:</div><div>        y = x + 1</div><div>        x = y + 2</div><div><br></div><div>is equivalent to:</div><div><br></div><div>    x = foo()</div><div>    y = x + 1</div><div>    x = y + 2</div><div>    del y</div><div><br></div><div>or after optimization:</div><div><br></div><div>    x = (foo() + 1) + 2</div><div><br></div><div>[Obviously more useful with real code but this is sufficiently illustrative. Also I imagine someone might say it&#39;s just foo() + 3 but I don&#39;t know the type of foo().]</div><div><br></div><div>--- Bruce</div><br><br>-- <br><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><font face="arial, helvetica, sans-serif">--- Bruce<br></font><div><div><font face="arial, helvetica, sans-serif">Check out my puzzle book and g</font><span style="font-family:arial,helvetica,sans-serif;font-size:12.8px">et it free here:</span></div><div><a href="http://J.mp/ingToConclusionsFree" style="font-family:arial,helvetica,sans-serif;font-size:12.8px" target="_blank">http://J.mp/ingToConclusionsFree</a><span style="font-family:arial,helvetica,sans-serif;font-size:12.8px"> (available on iOS)</span></div></div><div><br></div><div><br></div></div></div></div></div></div></div></div></div></div><br>