CSDN:
http://blog.csdn.net/weixin_38206454/article/details/78378939
简而言之，Python 2.x里字符串有两种：str和Unicode
前者到后者要decode，后者到前者要encode,’utf-8’为例：
str.decode(‘utf-8’) -> Unicode
str <- Unicode.encode(‘utf-8’)
http://blog.csdn.net/trochiluses/article/details/16825269
encode & decode
http://professor.blog.51cto.com/996189/1655816
python 字符编码详解
http://www.cnblogs.com/huxi/archive/2010/12/05/1897271.html
eval()函数
