详细文章:

http://www.cnblogs.com/yuanchenqi/articles/5956943.html

http://www.diveintopython3.net/strings.html

需知:

1.在python2默认编码是ASCII, python3里默认是unicode

2.unicode 分为 utf-32(占4个字节),utf-16(占两个字节)，utf-8(占1-4个字节)， so utf-16就是现在最常用的unicode版本， 不过在文件里存的还是utf-8，因为utf8省空间

3.在py3中encode,在转码的同时还会把string 变成bytes类型，decode在解码的同时还会把bytes变回string

 

 上图仅适用于py2

#-*-coding:utf-8-*-__author__ = 'Alex Li'import sysprint(sys.getdefaultencoding())msg = "我爱北京天安门"msg_gb2312 = msg.decode("utf-8").encode("gb2312")gb2312_to_gbk = msg_gb2312.decode("gbk").encode("gbk")print(msg)print(msg_gb2312)print(gb2312_to_gbk)in python2

python3

#-*-coding:gb2312 -*-   #这个也可以去掉__author__ = 'Alex Li'import sysprint(sys.getdefaultencoding())msg = "我爱北京天安门"#msg_gb2312 = msg.decode("utf-8").encode("gb2312")msg_gb2312 = msg.encode("gb2312") #默认就是unicode,不用再decode,喜大普奔gb2312_to_unicode = msg_gb2312.decode("gb2312")gb2312_to_utf8 = msg_gb2312.decode("gb2312").encode("utf-8")print(msg)print(msg_gb2312)print(gb2312_to_unicode)print(gb2312_to_utf8)in python3