Python's approach to binary data processing

The examples in this article describe how Python handles binary data. Share to everyone for your reference. Specific as follows:

#!/usr/env/env python #-*-coding:cp936-*-"" Add Head Infomation for PCM file ' import sys import struct import os __author__ = ' Bob_hu, hewitt924@gmail.com ' __date__ = ' Dec 19,2011 ' __update__ = ' Dec 19,2011 ' def geneheadinfo (Samplerat E,bits,samplenum): "' Generates header information, requires sample rate, number of bits per sample, and the number of bytes sampled for the entire wav ' rheadinfo = ' \x52\x49\x46\x46 ' filelength = Struc T.pack (' i ', Samplenum + $) rheadinfo + = filelength Rheadinfo + = ' \x57\x41\x56\x45\x66\x6d\x74\x20\x10\x00\x00\x00\x01\ x00\x01\x00 ' rheadinfo + = struct.pack (' i ', samplerate) Rheadinfo + = Struct.pack (' i ', samplerate * bits/8) RHeadInfo + = ' \x02\x00 ' rheadinfo + = Struct.pack (' H ', bits) rheadinfo + = ' \x64\x61\x74\x61 ' rheadinfo + = struct.pack (' I ', sample Num) return Rheadinfo if __name__ = = ' __main__ ': If Len (sys.argv)! = 5:print "Usage:python%s inFile samplerate Bits outFile "% sys.argv[0] sys.exit (1) fout = open (sys.argv[4], ' WB ') #用二进制的写入模式 #fout. Write (Struct.pack (' 4s ', ' \x6 6\x6d\x74\x20 ')) #写入一个长A string of 4 degrees, the binary content of this string is 6D, AFD,FAD,AFDD, = Struct.unpack (' 4c ', Fin.read (4)) #读入四个字节, each of which resolves to a letter #open (SYS . argv[4], ' WB '). Write (Struct.pack (' 4s ', ' fmt ') #将字符串解析成二进制后再写入 #open (sys.argv[4], ' WB '). Write (' \x3c\x9c\x00\x00\   X57 ') #直接写入二进制内容: 3C 9C xx #fout. Write (Struct.pack (' I ', 6000) #写入6000的二进制形式 #check whether InFile has Head-info Fin = open (sys.argv[1], ' RB ') Riff_flag, = struct.unpack (' 4s ', Fin.read (4)) if Riff_flag = = ' Riff ': print '%s has header information "% sys.argv[1] Fin.close () sys.exit (0) else:print"%s No header information "% sys.argv[1] fin.close () #采样率 SA mplerate = Int (sys.argv[2]) #bit位 bits = Int (sys.argv[3]) fin = open (sys.argv[1], ' RB ') startpos = Fin.tell () Fin.seek (0,os. Seek_end) Endpos = Fin.tell () Samplenum = (endpos-startpos) print Samplenum headinfo = Geneheadinfo (samp Lerate,bits,samplenum) Fout.write (headinfo) fin.seek (OS. Seek_set) Fout.write (Fin.read ()) Fin.close () Fout.close () 

Hopefully this article will help you with Python programming.

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