&gt; I think one thing that stalled adoption was the difficulty of migrating to Unicode string constants.<p>This wasn&#x27;t just down to the fact that Python 3 didn&#x27;t support u&quot;&quot; (it was 3.3 that was added, for reference), but also down to the fact that much of the eco-system still supported RHEL5&#x27;s default of Python 2.4 which meant `from __future__ import unicode_literals` wasn&#x27;t an option (it is, almost certainly, a less good option, but it&#x27;s in many ways good enough).