PYTHON(1) BSD General Commands Manual PYTHON(1)NAME
python, pythonw — an interpreted, interactive, object-oriented program‐
ming language
SYNOPSIS
python ...
pythonw ...
DESCRIPTION
To support multiple versions, the programs named python and pythonw now
just select the real version of Python to run, depending on various set‐
tings. (As of Python 2.5, python and pythonw are interchangeable; both
execute Python in the context of an application bundle, which means they
have access to the Graphical User Interface; thus both can, when properly
programmed, display windows, dialogs, etc.) The current supported ver‐
sions are 2.6 and 2.7, with the default being 2.6. Use
% man python2.6
% man python2.7
% man pythonw2.6
% man pythonw2.7
to see the man page for a specific version. Without a version specified,
% man pydoc
and the like, will show the man page for the (unmodified) default version
of Python (2.6). To see the man page for a specific version, use, for
example,
% man pydoc2.7
CHANGING THE DEFAULT PYTHON
Using
% defaults write com.apple.versioner.python Version 2.7
will make version 2.7 the user default when running the both the python
and pythonw commands (versioner is the internal name of the version-
selection software used).
To set a system-wide default, replace ‘com.apple.versioner.python’ with
‘/Library/Preferences/com.apple.versioner.python’ (admin privileges will
be required).
The environment variable VERSIONER_PYTHON_VERSION can also be used to set
the python and pythonw version:
% export VERSIONER_PYTHON_VERSION=2.7 # Bourne-like shells
or
% setenv VERSIONER_PYTHON_VERSION 2.7 # C-like shells
% python ...
This environment variable takes precedence over the preference file set‐
tings.
64-BIT SUPPORT
Versions 2.6 and 2.7 support 64-bit execution (which is on by default).
Like the version of Python, the python command can select between 32 and
64-bit execution (when both are available). Use:
% defaults write com.apple.versioner.python Prefer-32-Bit -bool yes
to make 32-bit execution the user default (using
‘/Library/Preferences/com.apple.versioner.python’ will set the system-
wide default). The environment variable VERSIONER_PYTHON_PREFER_32_BIT
can also be used (has precedence over the preference file):
% export VERSIONER_PYTHON_PREFER_32_BIT=yes # Bourne-like shells
or
% setenv VERSIONER_PYTHON_PREFER_32_BIT yes # C-like shells
Again, the preference setting and environmental variable applies to both
python and pythonw.
USING A SPECIFIC VERSION
Rather than using the python command, one can use a specific version
directly. For example, running python2.7 from the command line will run
the 2.7 version of Python, independent of what the default version of
Python is.
One can use a specific version of Python on the #! line of a script, but
that may have portability and future compatibility issues.
Note that the preference files and environment variable that apply to the
python command, do not apply when running a specific version of Python.
In particular, running python2.6 will always default to 64-bit execution
(unless one uses the arch(1) command to specifically select a 32-bit
architecture).
SEE ALSOpython2.6(1), python2.7(1), pythonw2.6(1), pythonw2.7(1), arch(1)BSD Aug 10, 2008 BSD
