1，terminal :
input: which Python
2, terminal:
input : python --->import sys ----> print sys.path
若Python 3.6, 则print(sys.path)
'', '/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python36.zip', '/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6', '/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/lib-dynload', '/usr/local/lib/python3.6/site-packages']