w3cschool ： http://www.runoob.com/python/python-tutorial.html

cnblog Python 从入门到精通：  http://www.cnblogs.com/toutou/p/4769355.html

http://www.crifan.com/files/doc/docbook/

http://www.crifan.com/files/doc/docbook/python_beginner_tutorial/release/html/python_beginner_tutorial.html#what_is_python