The parent comment&#x27;s explanation is exactly right (although I might not use &quot;CWD&quot; in this context, because a reader might mistakenly think the working directory is determined by an environment variable). As an example, try<p>python -c &#x27;import os; os.chdir(&quot;&#x2F;&quot;)&#x27;<p>Notice that the working directory of your shell is unaffected. :-)<p>Or:<p>bash -c &#x27;export foo=bar&#x27;; echo $foo