ubuntu 下python环境的切换使用

• 如何在Anaconda的python和系统自带的python之间切换

一般ubuntu下有三种python环境，1. 系统自带python2,3;在/usr/bin路径下；2. anaconda下安装的python;3. anaconda下创建的env环境

dsp@dsp-System-Product-Name:~/caffe-ssd$ whereis python
python: /usr/bin/python3.6m /usr/bin/python2.7-config /usr/bin/python2.7 /usr/bin/python3.6 /usr/bin/python3.6m-config 
/usr/bin/python /usr/bin/python3.6-config /usr/lib/python3.7 /usr/lib/python2.7 /usr/lib/python3.6 /etc/python2.7 
/etc/python3.6 /etc/python /usr/local/lib/python2.7 /usr/local/lib/python3.6 /usr/include/python3.6m /usr/include/python2.7 
/usr/include/python3.6 /usr/share/python /home/dsp/anaconda3/bin/python3.6m /home/dsp/anaconda3/bin/python3.6 
/home/dsp/anaconda3/bin/python3.6m-config /home/dsp/anaconda3/bin/python /home/dsp/anaconda3/bin/python3.6-config 
/usr/share/man/man1/python.1.gz

dsp@dsp-System-Product-Name:~/caffe-ssd$ python
Python 3.6.5 |Anaconda, Inc.| (default, Apr 29 2018, 16:14:56) 
[GCC 7.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
dsp@dsp-System-Product-Name:~/caffe-ssd$ activate py3.5
bash: /home/dsp/anaconda3/bin/activate: 权限不够
dsp@dsp-System-Product-Name:~/caffe-ssd$ source activate py3.5
(py3.5) dsp@dsp-System-Product-Name:~/caffe-ssd$ python
Python 3.5.6 |Anaconda, Inc.| (default, Aug 26 2018, 21:41:56) 
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.

-当我们将：/home/dsp/anaconda3/bin添加到环境变量中时，用python命令得到时anaconda下的python环境；

然后如果时env环境，直接进入创建的虚拟环境即可；

dsp@dsp-System-Product-Name:~/caffe-ssd$ echo $PATH
/home/dsp/pycharm-community-2017.3.3/bin:/home/dsp/anaconda3/bin:/usr/local/cuda-9.0/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin

- 如果时系统自带的环境，python2,3切换: linux下切换python2和python3

- 或者，待验证

python2切换到python3：
echo alias python=python3 >> ~/.bashrc
source ~/.bashrc
python3切换到python2：gedit  ~/.bashrc
# alias python=python3 
source ~/.bashrc