1 变量定义
http://docs.cython.org/src/reference/language_basics.html
http://blog.csdn.net/i2cbus/article/details/18456017
2 class
http://docs.cython.org/src/reference/extension_types.html
http://docs.cython.org/src/userguide/wrapping_CPlusPlus.html
http://blog.csdn.net/i2cbus/article/details/20158207