Since Python 3 the interpreter will halt when detecting mixed whitespace, forcing the programmer to deal with it.<p><a href="https:&#x2F;&#x2F;www.python.org&#x2F;dev&#x2F;peps&#x2F;pep-0008&#x2F;#tabs-or-spaces" rel="nofollow">https:&#x2F;&#x2F;www.python.org&#x2F;dev&#x2F;peps&#x2F;pep-0008&#x2F;#tabs-or-spaces</a>