curious about python version numbers

Ben Finney ben+python at
Tue Apr 13 12:13:08 CEST 2010

Alex Hall <mehgcap at> writes:

> I am just curious: if Python3.x is already out, why is 2.7 being
> released? Are there two main types of Python?

Python 3.x brings improvements that break backward compatibility:

    Python 3.0 (a.k.a. "Python 3000" or "Py3k") is a new version of the
    language that is incompatible with the 2.x line of releases. The
    language is mostly the same, but many details, especially how
    built-in objects like dictionaries and strings work, have changed
    considerably, and a lot of deprecated features have finally been
    removed. Also, the standard library has been reorganized in a few
    prominent places.


For that reason, when Python 3.x was being planned, the Python
developers committed to supporting Python 2.x with backward-compatible
releases for an indeterminate length of time to allow third-party
libraries to steadily migrate to Python 3.x so it becomes more
attractive to use it for all new development.

Python 2.7 has been announced to be the last feature release in the 2.x

    Python 2.7 is scheduled to be the last major version in the 2.x
    series before it moves into 5 years of bugfix-only mode.


 \       “The Initial Mystery that attends any journey is: how did the |
  `\   traveller reach his starting point in the first place?” —Louise |
_o__)                                  Bogan, _Journey Around My Room_ |
Ben Finney

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