Python 2.5 +:

python --version

Python 2.4 -:

python -c 'import sys; print(sys.version)'

主要是使用命令:

python -version

Or

python -V

对我来说，打开CMD并运行

py

会显示一些东西

Python 3.4.3 (v3.4.3:9b73f1c3e601, Feb 24 2015, 22:43:06) [MSC v.1600 32 bit (Intel)] on win32

Type "help", "copyright", "credits" or "license" for more information.

在命令提示符中键入:

python -V

如果你有pyenv

pyenv versions

In [1]: import sys

In [2]: sys.version
2.7.11 |Anaconda 2.5.0 (64-bit)| (default, Dec  6 2015, 18:08:32) 
[GCC 4.4.7 20120313 (Red Hat 4.4.7-1)]

In [3]: sys.version_info
sys.version_info(major=2, minor=7, micro=11, releaselevel='final', serial=0)

In [4]: sys.version_info >= (2,7)
Out[4]: True

In [5]: sys.version_info >= (3,)
Out[5]: False

python -V

http://docs.python.org/using/cmdline.html#generic-options

——version也可以工作(在2.5版本中引入)