Python ] struct 모듈

 

This module converts between Python values and C structs represented as Python bytes objects. Compact format strings describe the intended conversions to/from Python values. The module’s functions and objects can be used for two largely distinct applications, data exchange with external sources (files or network connections), or data transfer between the Python application and the C layer.

 

 

 

Functions

The module defines the following exception and functions:

 

struct.pack(format, v1, v2, ...)

Return a bytes object containing the values v1, v2, … packed according to the format string format. The arguments must match the values required by the format exactly.

 

struct.pack_into(format, buffer, offset, v1, v2, ...)

Pack the values v1, v2, … according to the format string format and write the packed bytes into the writable buffer buffer starting at position offset. Note that offset is a required argument.

 

struct.unpack(format, buffer)

Unpack from the buffer buffer (presumably packed by pack(format, ...)) according to the format string format. The result is a tuple even if it contains exactly one item. The buffer’s size in bytes must match the size required by the format, as reflected by calcsize().

 

struct.unpack_from(format, /, buffer, offset=0)

Unpack from buffer starting at position offset, according to the format string format. The result is a tuple even if it contains exactly one item. The buffer’s size in bytes, starting at position offset, must be at least the size required by the format, as reflected by calcsize().

 

struct.iter_unpack(format, buffer)

Iteratively unpack from the buffer buffer according to the format string format. This function returns an iterator which will read equally sized chunks from the buffer until all its contents have been consumed. The buffer’s size in bytes must be a multiple of the size required by the format, as reflected by calcsize(). Each iteration yields a tuple as specified by the format string.

 

struct.calcsize(format)

Return the size of the struct (and hence of the bytes object produced by pack(format, ...)) corresponding to the format string format.

 

 

 

 

 

 

 

Format Strings

 

Byte Order, Size, and Alignment

 

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

 

 

Format Characters

 

Format	C Type	Python type	Standard size
x	pad byte	no value
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
n	ssize_t	integer
N	size_t	integer
e	(6)	float	2
f	float	float	4
d	double	float	8
s	char[]	bytes
p	char[]	bytes
P	void*	integer

 

 

 

 

출처 : https://docs.python.org/3/library/struct.html