import base64

copyright = 'Copyright (c) 2012 Doucube Inc. All rights reserved.'

def main():
    #转成bytes string
    bytesString = copyright.encode(encoding="utf-8")
    print(bytesString)

    #base64 编码
    encodestr = base64.b64encode(bytesString)
    print(encodestr)
    print(encodestr.decode())

    #解码
    decodestr = base64.b64decode(encodestr)
    print(decodestr.decode())


if __name__ == '__main__':
    main()

*** Python 3.2.3 (default, Apr 11 2012, 07:15:24) [MSC v.1500 32 bit (Intel)] on win32. ***
>>> 
*** Remote Interpreter Reinitialized  ***
>>> 
b'Copyright (c) 2012 Doucube Inc. All rights reserved.'
b'Q29weXJpZ2h0IChjKSAyMDEyIERvdWN1YmUgSW5jLiBBbGwgcmlnaHRzIHJlc2VydmVkLg=='
Q29weXJpZ2h0IChjKSAyMDEyIERvdWN1YmUgSW5jLiBBbGwgcmlnaHRzIHJlc2VydmVkLg==
Copyright (c) 2012 Doucube Inc. All rights reserved.
>>> 

import base64

print(base64.b64decode(b'Q29weXJpZ2h0IChjKSAyMDEyIERvdWN1YmUgSW5jLiBBbGwgcmlnaHRzIHJlc2VydmVkLg==').decode())