How do I check what version of Python is running m

Question

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

Answer 1

Put something like:

#!/usr/bin/env/python
import sys
if sys.version_info<(2,6,0):
  sys.stderr.write("You need python 2.6 or later to run this script\n")
  exit(1)

at the top of your script.

Note that depending on what else is in your script, older versions of python than the target may not be able to even load the script, so won't get far enough to report this error. As a workaround, you can run the above in a script that imports the script with the more modern code.

Answer 2

If you want to detect pre-Python 3 and don't want to import anything...

...you can (ab)use list comprehension scoping changes and do it in a single expression:

is_python_3_or_above = (lambda x: [x for x in [False]] and None or x)(True)

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

Use platform's python_version from the stdlib:

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

Answer 5

The simplest way

Just type python in your terminal and you can see the version as like following

desktop:~$ python
Python 2.7.6 (default, Jun 22 2015, 18:00:18) 
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 

Answer 6

To verify the Python version for commands on Windows, run the following commands in a command prompt and verify the output

c:\>python -V
Python 2.7.16

c:\>py -2 -V
Python 2.7.16

c:\>py -3 -V
Python 3.7.3

Also, To see the folder configuration for each Python version, run the following commands:

For Python 2,'py -2 -m site'
For Python 3,'py -3 -m site'