>>> import sys; print('{0[0]}.{0[1]}'.format(sys.version_info))
3.5

从命令行开始:

python -c "import sys; print('{0[0]}.{0[1]}'.format(sys.version_info))"

虽然问题是“我使用的是哪个版本?”，但这可能并不是你需要知道的全部内容。您可能已经安装了其他版本，这可能会导致问题，特别是在安装其他模块时。这是我粗略地找出安装了什么版本的方法:

updatedb                  # Be in root for this
locate site.py            # All installations I've ever seen have this

单个Python安装的输出应该是这样的:

/usr/lib64/python2.7/site.py
/usr/lib64/python2.7/site.pyc
/usr/lib64/python2.7/site.pyo

多个安装将会有类似这样的输出:

/root/Python-2.7.6/Lib/site.py
/root/Python-2.7.6/Lib/site.pyc
/root/Python-2.7.6/Lib/site.pyo
/root/Python-2.7.6/Lib/test/test_site.py
/usr/lib/python2.6/site-packages/site.py
/usr/lib/python2.6/site-packages/site.pyc
/usr/lib/python2.6/site-packages/site.pyo
/usr/lib64/python2.6/site.py
/usr/lib64/python2.6/site.pyc
/usr/lib64/python2.6/site.pyo
/usr/local/lib/python2.7/site.py
/usr/local/lib/python2.7/site.pyc
/usr/local/lib/python2.7/site.pyo
/usr/local/lib/python2.7/test/test_site.py
/usr/local/lib/python2.7/test/test_site.pyc
/usr/local/lib/python2.7/test/test_site.pyo

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)

要在Jupyter笔记本中检查Python版本，您可以使用:

from platform import python_version
print(python_version())

获取版本号，如下:

3.7.3

or:

import sys
print(sys.version)

为了获得更多的信息，如

3.7.3 (default, Apr 24 2019, 13:20:13) [MSC v.1915 32 bit (Intel)]

or:

sys.version_info

要获得大版本、小版本和微版本，如

sys.version_info(major=3, minor=7, micro=3, releaselevel='final', serial=0)

>>> import sys; print('{0[0]}.{0[1]}'.format(sys.version_info))
3.5

从命令行开始:

python -c "import sys; print('{0[0]}.{0[1]}'.format(sys.version_info))"

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