struct

Byte order

| Character | Byte order | |:———–|:———–| | @ | native | | = | native | | < | little-endian | | > | big-endian | | ! | network (= big-endian) |

import struct
struct.pack('>h', 1023)
b'\x03\xff'
struct.pack('<h', 1023)
b'\xff\x03'

Format

A format character may be preceded by an integral repeat count. For example, the format string ‘4h’ means exactly the same as ‘hhhh’.

Format	C Type	Python Type	Standard Size
c	char	bytes of length 1	1
b	signed char	integer	1
B	unsigned char	integer	1
?	_Bool	bool	1
h	short	integer	2
H	unsigned short	integer	2
i	int	integer	4
I	unsigned int	integer	4
l	long	integer	4
L	unsigned long	integer	4
q	long long	integer	8
Q	unsigned long long	integer	8
f	float	float	4
d	double	float	8
s	char[]	bytes
p	char[]	bytes

pack(">bhl", 1, 2, 3) # b'\x01\x00\x02\x00\x00\x00\x03'
unpack('>bhl', b'\x01\x00\x02\x00\x00\x00\x03') # (1, 2, 3)
struct.calcsize('>bhl') # 7
pack("@ccc", b'1', b'2', b'3') # b'123'
pack("@3s", b'123') # b'123'

Native byte order

sys.byteorder