TRACING venv pip

pip install virtualenv
cd my_project_folder
virtualenv venv
virtualenv -p /usr/bin/python2.7 venv
source venv/bin/activate
deactivate

pip freeze > requirements.txt

# vi ~/.pip/pip.conf
[global]
index-url = http://mirrors.aliyun.com/pypi/simple/
[install]
trusted-host=mirrors.aliyun.com