struct – pack and unpack primitive data types¶
This module implements a subset of the corresponding CPython module,
as described below. For more information, refer to the original
CPython documentation: struct.
The following byte orders are supported:
Character |
Byte order |
Size |
Alignment |
|---|---|---|---|
@ |
native |
native |
native |
< |
little-endian |
standard |
none |
> |
big-endian |
standard |
none |
! |
network (= big-endian) |
standard |
none |
The following data types are supported:
Format |
C Type |
Python type |
Standard size |
|---|---|---|---|
b |
signed char |
integer |
1 |
B |
unsigned char |
integer |
1 |
h |
short |
integer |
2 |
H |
unsigned short |
integer |
2 |
i |
int |
integer (1) |
4 |
I |
unsigned int |
integer (1) |
4 |
l |
long |
integer (1) |
4 |
L |
unsigned long |
integer (1) |
4 |
q |
long long |
integer (1) |
8 |
Q |
unsigned long long |
integer (1) |
8 |
e |
n/a (half-float) |
float (2) |
2 |
f |
float |
float (2) |
4 |
d |
double |
float (2) |
8 |
s |
char[] |
bytes |
|
P |
void * |
integer |
Requires long support when used with values larger than 30 bits.
Requires floating point support.
Difference to CPython
Whitespace is not supported in format strings.
Functions¶
- struct.calcsize(fmt)¶
Return the number of bytes needed to store the given fmt.
- struct.pack(fmt, v1, v2, ...)¶
Pack the values v1, v2, … according to the format string fmt. The return value is a bytes object encoding the values.
- struct.pack_into(fmt, buffer, offset, v1, v2, ...)¶
Pack the values v1, v2, … according to the format string fmt into a buffer starting at offset. offset may be negative to count from the end of buffer.
- struct.unpack(fmt, data)¶
Unpack from the data according to the format string fmt. The return value is a tuple of the unpacked values.
- struct.unpack_from(fmt, data, offset=0, /)¶
Unpack from the data starting at offset according to the format string fmt. offset may be negative to count from the end of data. The return value is a tuple of the unpacked values.