创建指定 py版本环境
sudo virtualenv -p /usr/bin/python3 env3
激活
source ./env3/bin/activate
关闭环境
deactivate
(env3) [~/virtualpy3]$ sudo /data1/home/nieli/virtualpy3/env3/bin/python -m pip install --upgrade pip
(env3) [~/virtualpy3]$ sudo /data1/home/nieli/virtualpy3/env3/bin/python -m pip install --upgrade setuptools
(env3) [~/virtualpy3]$ sudo /data1/home/nieli/virtualpy3/env3/bin/python -m pip install pymysql
$ which python
/data1/home/nieli/virtualpy3/env3/bin/python
不指定虚拟环境的python地址会用本机(默认一般是2.x)版本的造成下载的各种错误