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

Question

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

Answer 1

Several answers already suggest how to query the current python version. To check programmatically the version requirements, I'd make use of one of the following two methods:

# Method 1: (see krawyoti's answer)
import sys
assert(sys.version_info >= (2,6))

# Method 2: 
import platform
from distutils.version import StrictVersion 
assert(StrictVersion(platform.python_version()) >= "2.6")

Answer 2

The even simpler simplest way:

In Spyder, start a new "IPython Console", then run any of your existing scripts.

Now the version can be seen in the first output printed in the console window:

"Python 3.7.3 (default, Apr 24 2019, 15:29:51)..."

Answer 3

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:

>>> 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.

Answer 4

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

python -V

This is documented in 'man python'.

From IPython console

!python -V

Answer 5

I like sys.hexversion for stuff like this.

http://docs.python.org/library/sys.html#sys.hexversion

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

Answer 6

Use platform's python_version from the stdlib:

>>> from platform import python_version
>>> print(python_version())
2.7.8