That&#x27;s because Python 2 has a special case for lists[1]. This does not exist in Python 3[2] (and therefore neither does the performance difference).<p>[1] <a href="https:&#x2F;&#x2F;github.com&#x2F;python&#x2F;cpython&#x2F;blob&#x2F;2.7&#x2F;Python&#x2F;ceval.c#L1521-L1545" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;python&#x2F;cpython&#x2F;blob&#x2F;2.7&#x2F;Python&#x2F;ceval.c#L1...</a><p>[2] <a href="https:&#x2F;&#x2F;github.com&#x2F;python&#x2F;cpython&#x2F;blob&#x2F;master&#x2F;Python&#x2F;ceval.c#L1591-L1601" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;python&#x2F;cpython&#x2F;blob&#x2F;master&#x2F;Python&#x2F;ceval.c...</a>