python–ntohll和htonll的实现(转载)

可以利用python中的struct包中的如下东东进行转换：  
1、字节序：  

Character	Byte order	Size and alignment
@	native	native
=	native	standard
<	little-endian	standard
>	big-endian	standard
!	network (= big-endian)	standard

2、字节数  

Format	C Type	Python	Notes
x	pad byte	no value
c	char	bytes of length 1
b	signed char	integer	(1)
B	unsigned char	integer
?	_Bool	bool	(2)
h	short	integer
H	unsigned short	integer
i	int	integer
I	unsigned int	integer
l	long	integer
L	unsigned long	integer
q	long long	integer	(3)
Q	unsigned long long	integer	(3)
f	float	float
d	double	float
s	char[]	bytes	(1)
p	char[]	bytes	(1)
P	void *	integer

3、自定义函数  

使用struct,相当轻松

import struct  
htonll = lambda a:struct.unpack('!Q', struct.pack('Q', a) )[0]

ntohll = lambda a:struct.unpack('Q', struct.pack('!Q', a))[0]