普通字符串可以用多种方式编码成Unicode字符串，具体要看你究竟选择了哪种编码：unicodestring=u"Helloworld"#将Unicode转化为普通Python字符串："encode"utf8string=unicodestring.encode("utf-8"
)asciistring=unicodestring.encode("ascii"
)isostring=unicodestring.encode("ISO-8859-1"
)utf16string=unicodestring.encode("utf-16")#将普通Python字符串转化为Unicode："decode"plainstring1=unicode(utf8string,"utf-8"
)plainstring2=unicode(asciistring,"ascii"
)plainstring3=unicode(isostring,"ISO-8859-1"
)plainstring4=unicode(utf16string,"utf-16"
)assertplainstring1==plainstring2==plainstring3==plainstring4