The UK’s cyber-security agency warned today developers to consider moving Python 2.x codebases to the newer 3.x branch due to the looming end-of-life (EOL) of the Python 2, scheduled for January 1, 2020. The UK National Cyber Security Centre (NCSC) cited security risks and possible code breakage in existing apps as the primary reasons, ZDNet reported.

The effort to get developers to migrate to Python 3 has been underway for years, but Python 2 is deeply entrenched. Unfortunately, it’s likely to take a significant security incident to drive the last mile of migration.
Popularity comes at a price, in this case. The widespread use and adoption of Python makes a migration like this nearly impossible to get right. Despite years of transition time and dual support for both versions, the EOL date will still come with a very large base of Python 2 code being used in production.