How do I check what version of Python is running my script?

This information is available in the sys.version string in the sys module:

>>> import sys

Human readable:

>>> print(sys.version)  # parentheses necessary in python 3.       2.5.2 (r252:60911, Jul 31 2008, 17:28:52) [GCC 4.2.3 (Ubuntu 4.2.3-2ubuntu7)]

For further processing, use sys.version_info or sys.hexversion:

>>> sys.version_info(2, 5, 2, 'final', 0)# or>>> sys.hexversion34014192

To ensure a script runs with a minimal version requirement of the Python interpreter add this to your code:

assert sys.version_info >= (2, 5)

This compares major and minor version information. Add micro (=0, 1, etc) and even releaselevel (='alpha','final', etc) to the tuple as you like. Note however, that it is almost always better to "duck" check if a certain feature is there, and if not, workaround (or bail out). Sometimes features go away in newer releases, being replaced by others.

From the command line (note the capital 'V'):

python -V

This is documented in 'man python'.

From IPython console

!python -V

I like sys.hexversion for stuff like this.

>>> import sys>>> sys.hexversion33883376>>> '%x' % sys.hexversion'20504f0'>>> sys.hexversion < 0x02060000True