Completing the move to Python 3
===============================

Debian has previously supported two Python stacks, one for Python 3 and
one for Python 2.
The goal for Debian is to reduce this to one stack, dropping the Python
2 stack and interpreter for the Bullseye release.

:pep:`404` states that no more major Python 2 releases are planned,
although the latest released minor version 2.7 will see some extended
support, documented in :pep:`466`.

Packages in Debian should use Python 3.
New packages must use Python 3 from the initial upload, new upstream
versions for existing packages must use Python 3.
If Python 2 is still supported in Bullseye, selected packages may
continue using Python 2 until Python 3 support is available for those
packages.
Please discuss all use of Python 2 on the debian-python mailing list
before uploading.

#. Applications should use Python 3 and must not be packaged for Python
   2 as well.
   If an application supports only Python 2, the application may need
   to be removed from Debian so that it does not block removal of other
   Python 2 packages.

#. Python libraries need to support Python 3 and new versions must be
   packaged for Python 3.
   Existing Python 2 libraries must not be dropped before the last
   reverse dependency is removed.
   New Python 2 libraries must not be introduced.

#. Python 3 should be used for the packaging if the packaging scripts
   use Python.