import base64

 '''编码解码'''

 st = 'ni hao'.encode('utf8')

 result = base64.b64encode(st)

 print(result)   # b'bmkgaGFv'

 result = base64.b64decode(result)

 print(result)   # b'ni hao'

 print(result.decode('utf8'))    # ni hao

 url = 'https://www.baidu.com'.encode('utf8')

 result = base64.urlsafe_b64encode(url)

 print(result)   # b'aHR0cHM6Ly93d3cuYmFpZHUuY29t'

 result = base64.urlsafe_b64decode(result)

 print(result.decode('utf8'))    # https://www.baidu.com