How Do I Check What Version Of Python Is Running My Script?

How can I check what version of the Python Interpreter is interpreting my script?

Solution 1:

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.hexversion
34014192

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.

Solution 2:

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

python -V

This is documented in 'man python'.

From IPython console

!python -V

Solution 3:

I like sys.hexversion for stuff like this.

>>>import sys>>>sys.hexversion
33883376
>>>'%x' % sys.hexversion
'20504f0'
>>>sys.hexversion < 0x02060000
True

Solution 4:

Use platform's python_version from the stdlib:

from platform import python_version
print(python_version())

# 3.9.2

Solution 5:

Your best bet is probably something like so:

>>>import sys>>>sys.version_info
(2, 6, 4, 'final', 0)
>>>ifnot sys.version_info[:2] == (2, 6):...print"Error, I need python 2.6"...else:...from my_module import twoPointSixCode>>>

Additionally, you can always wrap your imports in a simple try, which should catch syntax errors. And, to @Heikki's point, this code will be compatible with much older versions of python:

>>>try:...from my_module import twoPointSixCode...except Exception: ...print"can't import, probably because your python is too old!">>>