Bug#841142: python 3.5 magic number

[曹忠]

Package: python3
  Version: 3.5.2

On debian 9 and python 3.5.2:
>>> imp.get_magic()
b'\x17\r\r\n'

On windows and python 3.5.2
>>> imp.get_magic()
b'\x16\r\r\n'

the same python version, magic number is the same, why not?