python打印字节流_python中将多个参数打包为字节流的第二种方法

最新推荐文章于 2024-10-31 16:52:48 发布

原创最新推荐文章于 2024-10-31 16:52:48 发布 · 280 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#python打印字节流

本文介绍了一种使用结构体直接打包参数的方法，详细说明了如何定义参数包的结构和布局，包括包头、参数内容及包尾的设计。参数包整体大小固定为64字节，采用小端字节序，并给出了具体参数如频率范围、脉冲数量等的定义。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1 #-*- coding: utf-8 -*-#

3 #-------------------------------------------------------------------------------

4 #Name: 以结构体形式直接打包参数包

5 #Description: 整个包大小为64Byte，包头为0X”FAA5 FBB5 FCC4 FDD5”，包尾为0X”5FA5 5FB5 5FC5 5FD5 ”，中间不足部分补0

6 #发送的参数定义(有符号整型数字)

7 #cmdType = 1 # 1 Byte

8 #sigType = 2 # 1 Byte

9 #startFreq = 40 # 4 Byte

10 #stopFreq = 400 # 4 Byte

11 #deltFreq = 10 # 4 Byte

12 #pulseNum = 37 # 2 Byte

13 #pulseWidth = 0 # 4 Byte

14 #PRF = 25000000 # 4 Byte

15 #receiverFreq = 1000 # 4 Byte

16 #Author: lgk

17 #Date: 2018/6/14

18 #-------------------------------------------------------------------------------

20 importstruct21 importctypes22 importbinascii23 importre24

25 #字节顺序定义

26 byteOrders = {'Native order':'@',27 'Native standard':'=',28 'Little-endian':'',30 'Network order':'!'}31

32 byteOrder = 'Little-endian'

34 fmt_head = fmt_tail = struct.Struct(byteOrders[byteOrder] + "8B")35 fmt_body = struct.Struct(byteOrders[byteOrder] + "2b3i1h3i")36 bufferLength = 64

38 defgetSendInfo(info):39 p = re.compile('.{1,2}') #匹配任意字符1-2次

40 t = ' '.join(p.findall(info.upper()))41 returnt42

43 #定义本地形式结构体

44 classCMDParaNative(ctypes.Structure):45 _pack_ = 1

46 _fields_ =[47 ('cmdType', ctypes.c_int8),48 ('sigType', ctypes.c_int8),49 ('startFreq', ctypes.c_int32),50 ('stopFreq', ctypes.c_int32),51 ('deltFreq', ctypes.c_int32),52 ('pulseNum', ctypes.c_int16),53 ('pulseWidth', ctypes.c_int32),54 ('PRF', ctypes.c_int32),55 ('receiverFreq', ctypes.c_int32)56 ]57

58 #定义大端形式结构体

59 classCMDParaBigEndian(ctypes.BigEndianStructure):60 _pack_ = 1

61 _fields_ =[62 ('cmdType', ctypes.c_int8),63 ('sigType', ctypes.c_int8),64 ('startFreq', ctypes.c_int32),65 ('stopFreq', ctypes.c_int32),66 ('deltFreq', ctypes.c_int32),67 ('pulseNum', ctypes.c_int16),68 ('pulseWidth', ctypes.c_int32),69 ('PRF', ctypes.c_int32),70 ('receiverFreq', ctypes.c_int32)71 ]72

73 #定义小端形式结构体

74 classCMDParaLittleEndian(ctypes.LittleEndianStructure):75 _pack_ = 1

76 _fields_ =[77 ('cmdType', ctypes.c_int8),78 ('sigType', ctypes.c_int8),79 ('startFreq', ctypes.c_int32),80 ('stopFreq', ctypes.c_int32),81 ('deltFreq', ctypes.c_int32),82 ('pulseNum', ctypes.c_int16),83 ('pulseWidth', ctypes.c_int32),84 ('PRF', ctypes.c_int32),85 ('receiverFreq', ctypes.c_int32)86 ]87

88 if byteOrder == 'Little-endian':89 para = CMDParaLittleEndian(1, 2, 40, 400, 10, 37, 0, 25000000, 1000)90 elif byteOrder == 'Big-endian':91 para = CMDParaBigEndian(1, 2, 40, 400, 10, 37, 0, 25000000, 1000)92 else:93 para = CMDParaNative(1, 2, 40, 400, 10, 37, 0, 25000000, 1000)94

95 headInfo = [0xFA, 0xA5, 0xFB, 0xB5, 0xFC, 0xC5, 0xFD, 0xD5]96 tailInfo = [0x5F, 0xA5, 0x5F, 0xB5, 0x5F, 0xC5, 0x5F, 0xD5]97

98 sendBuffer = ctypes.create_string_buffer(bufferLength) #创建发送缓冲区

100 #将待发送的参数打包到缓冲区

101 fmt_head.pack_into(sendBuffer, 0, *headInfo)102 fmt_tail.pack_into(sendBuffer, bufferLength-fmt_tail.size, *tailInfo)103 #将结构体数据对应的内存移动到缓冲区对应的位置

104 ctypes.memmove(ctypes.addressof(sendBuffer)+fmt_head.size, ctypes.byref(para), ctypes.sizeof(para))105 #ctypes.memmove(ctypes.byref(sendBuffer, fmt_head.size), ctypes.byref(para), ctypes.sizeof(para)) #与上面一行等价

106

107 #打印出字节流的16进制信息(byteOrder = 'Little-endian')

108 #FA A5 FB B5 FC C5 FD D5 01 02 28 00 00 00 90 01 00 00 0A 00 00 00 25 00 00 00 00 00 40 78 7D 01 E8 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 5F A5 5F B5 5F C5 5F D5

109 print(getSendInfo(binascii.hexlify(sendBuffer)))