Python---查看安装路径

python是解释型脚本语言，在执行时，逐句解释执行，不需要进行预编译。但需要有自身的Python解释器。 
所以在执行Python代码时，需要指定python解释器。 
指定解释器方法： 
在文件开头添加搜索路径,

linux

中一般安装后的默认路径如下

#!/usr/bin/env python 
或者
#!/usr/locat/bin/python  

如果没有找到，可以通过命令查询python路径

whereis python
或者
which python

Windows OS

可以通过以下方式查询python路径或者第三方模块安装路径。

>>> import sys
>>> sys.path
['', 'C:\Python27\Lib\idlelib', 'C:\Python27\lib\site-packages\robotframework_selenium2library-1.5.0-py2.7.egg', 'C:\Python27\lib\site-packages\docutils-0.14-py2.7.egg', 'C:\Python27\lib\site-packages\decorator-4.2.1-py2.7.egg', 'C:\Windows\system32\python27.zip', 'C:\Python27\DLLs', 'C:\Python27\lib', 'C:\Python27\lib\plat-win', 'C:\Python27\lib\lib-tk', 'C:\Python27', 'C:\Python27\lib\site-packages', 'C:\Python27\lib\site-packages\win32', 'C:\Python27\lib\site-packages\win32\lib', 'C:\Python27\lib\site-packages\Pythonwin', 'C:\Python27\lib\site-packages\wx-2.8-msw-unicode']

cmd目录下运行python -V可查看python版本

修改默认python版本 
先查看安装的python路径：

Hansonman@localhost:~$ whereis python python: /usr/bin/python /usr/bin/python3.5 /usr/bin/python2.7-config /usr/bin/python3.5m /usr/bin/python2.7 /usr/lib/python3.5 /usr/lib/python2.7 /etc/python /etc/python3.5 /etc/python2.7 /usr/local/bin/python3.6m-config /usr/local/bin/python3.6-config /usr/local/bin/python3.6m /usr/local/bin/python3.6 /usr/local/lib/python3.5 /usr/local/lib/python3.6 /usr/local/lib/python2.7 /usr/include/python3.5m /usr/include/python2.7 /usr/share/python /usr/share/man/man1/python.1.gz

使用ln -s命令来修改，命令如下：

Hansonman@localhost:~$ sudo rm /usr/bin/python
[sudo] password forHansonman: 

Hansonman@localhost:~$ sudo ln -s /usr/bin/python3.5 /usr/bin/python justin18chan@justin18chan:~$ python Python 3.5.2 (default, Feb 28 2018, 10:10:06)