A list of vendors, in alphabetical order, who provide services supporting Python 2 codebases or migrating from Python 2 to Python 3.
Disclaimer: This page, like the rest of the Wiki, is user-contributed content; being listed here does not imply any sort of endorsement by the Python Software Foundation.
Level 12: providing 2 -> 3 migration, but not long term Python 2 support
Python Academy (Germany)
Reckon Digital (United Kingdom)
Some of the consulants listed at PythonConsulting may also be able to help, but if they're not listed here you'll have to ask them.