Python struct module

1 Importstruct#a module2 3 4 #Functions to convert between Python values and C structs.5 #Python bytes Objects is used to hold the data representing the C struct6 #and also as format strings (explained below) to describe the layout of the data in the C struct.7 #@: Native order, Size & Alignment (default)8 #=: Native order, std. Size & Alignment9 #<: Little-endian, std. Size & AlignmentTen #: Big-endian, std. Size & Alignment One #!: Same as > A  - #X:pad byte (no data); c:char; b:signed byte; b:unsigned byte; - #?: _bool (requires C99; if not available, char is used instead) the #H:short; h:unsigned Short; I:int; i:unsigned int; - #L:long; L:unsigned long; F:float; d:double; E:half-float. Special cases (preceding decimal count indicates length): - #s:string (array of char); P:pascal string (with Count byte). Special cases (only available in native format): - #n:ssize_t; n:size_t; + #P:an integer type is wide enough to hold a pointer. Special case (not in native mode unless ' long long ' in platform C): - #Q:long Long; q:unsigned Long Long + #class struct (object) struct (FMT)---Compiled struct object A #Return A new Struct object which writes and reads binary data according to the format string FMT at  - #iter_unpack (...) S.iter_unpack (buffer), iterator (v1, v2, ...) - # - #Pack_into (...) S.pack_into (buffer, offset, v1, v2, ...) - #Unpack_from (...) S.unpack_from (buffer, offset=0) (v1, v2, ...) - # in #Pack (...) S.pack (v1, v2, ...) bytes - #Unpack (...) S.unpack (buffer) (v1, v2, ...) to  +  - Importstruct the  *  $ #1, Struct.packPanax NotoginsengA = 20 -B = 400 the  +Str_ = Struct.pack (">ii", A, B)#the converted str, although a string type, is equivalent to a stream of bytes in other languages (a byte array) that can be transmitted over the network A Print('Length:', Len (str_)) the Print('Type:', type (STR_)) + Print(STR_) - Print(repr (str_)) $  $ #Length:8 - #type: <class ' bytes ' > - #b ' \x00\x00\x00\x14\x00\x00\x01\x90 ' the #b ' \x00\x00\x00\x14\x00\x00\x01\x90 ' - Wuyi  theStr_ = Struct.pack ("<ii", A, B)#the converted str, although a string type, is equivalent to a stream of bytes in other languages (a byte array) that can be transmitted over the network - Print('Length:', Len (str_)) Wu Print('Type:', type (STR_)) - Print(STR_) About Print(repr (str_)) $  - #Length:8 - #type: <class ' bytes ' > - #b ' \x14\x00\x00\x00\x90\x01\x00\x00 ' A #b ' \x14\x00\x00\x00\x90\x01\x00\x00 ' +  the  - #2, Struct.unpack $A1, a2 = Struct.unpack ("<ii", STR_)#return to progenitor the Print(A1, A2)#20,400 the  the  the #3. Struct.calcsize used to calculate the length of the result of the format string - Print(Struct.calcsize ('>ii'))#8 in  the  the #4, Struct.pack_into, Struct.unpack_from About  fromcTYPESImportCreate_string_buffer the  theBUF = Create_string_buffer (12) the Print(Repr (Buf.raw))#b ' \x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00 ' +  -Struct.pack_into (">III", buf, 0, 1, 2,-1)#0 is offset the Print(Repr (Buf.raw))#b ' \x01\x00\x00\x00\x02\x00\x00\x00\xff\xff\xff\xff 'Bayi  the Print(Struct.unpack_from ('>III', buf, 0))#(1, 2,-1) the  - #5, Struct.iter_unpack -ret = Struct.iter_unpack ('>III', BUF) the Print(ret)#<unpack_iterator object at 0x0000000001d02e18> the  forRinchret: the     Print(r)#(1, 2,-1) the  -  the #6. Practice the Print(Struct.pack ('ci'B'*', 0x12131415))#b ' *\x00\x00\x00\x15\x14\x13\x12 ' the Print(Struct.pack ('IC', 0x12131415, b'*'))#b ' \x15\x14\x13\x12* '94  theRecord = b'Raymond \x32\x12\x08\x01\x08' the Print(Struct.unpack ('<10SHHB', record))#(b ' Raymond ', 4658, 8)

character	byte order	size	Snap To
@	Natively	Natively	Natively
=	Natively	Standard	No
<	Small end	Standard	No
>	Big End	Standard	No
!	Network (equals big-endian)	Standard	No

format	Type C	python type	Standard size	Tips
X	Padding bytes	No value
C	Char	1 bytes in length	1
B	Signed Char	Integer	1	1,3
B	unsigned char	Integer	1	3
?	_bool	bool	1	1
H	Short	Integer	2	3
H	unsigned short	Integer	2	3
I	Int	Integer	4	3
I	unsigned int	Integer	4	3
L	Long	Integer	4	3
L	unsigned long	Integer	4	3
Q	Long Long	Integer	8	2,3
Q	unsigned long long	Integer	8	2,3
N	ssize_t	Integer		4
N	size_t	Integet		4
E	7	Float	2	5
F	Float	Float	4	5
D	Double	Float	8	5
S	Char[]	bytes
P	Char[]	bytes
P	void *	Integer		6

Python struct module