Appendix

1. pack/unpack Format Characters

1.1 Format Characters

Format	C Type	Python Type	DolphinDB Type	Range
x	pad byte	no value	VOID
c	char	bytes of length 1	CHAR	-27 +1~27 -1
b	signed char	integer	LONG	-27 ~27 -1
B	unsigned char	integer	LONG	0~28 -1
?	_Bool	bool	LONG	-263 ~263 -1
h	short	integer	LONG	-215 ~215 -1
H	unsigned short	integer	LONG	0~216 -1
i	int	integer	LONG	-231 ~231 -1
I	unsigned int	integer	LONG	0~232 -1
l	long	integer	LONG	-231~231 -1
L	unsigned long	integer	LONG	0~232 -1
q	long long	integer	LONG	-263 ~263 -1
Q	unsigned long long	integer	LONG	0~263 -1
n	ssize_t	integer	LONG	-263 ~263 -1
N	size_t	integer	LONG	0~263 -1
f	float	float	LONG	-3.40E+38 ~ +3.40E+38
d	double	float	LONG	-1.79E+308 ~ +1.79E+308
s	char[]	bytes	STRING
p	char[]	bytes	STRING
P	void*	integer	LONG	-263 ~263 -1

1.2 Byte Order, Size, and Alignment

Character	Byte order	Size	Alignment
>	big-endian	standard	none
=	native	standard	none
<	little-endian	standard	none
@	native	native	native
!	network (= big-endian)	native	none