Parsing binary data into separate variables in Python? -

say open file in python contains series of binary data.

with open(sys.argv[1]) data_file:     logdata = data_file.read() 

i want create loop saying:

for each_word in logdata:        var1 = first 8 bytes        var2 = next 16 bytes        var3 = next 8 bytes 

c code generate binary file:

#include <stdio.h> #include <stdlib.h>  int main(void) {         file *file;         int  buffer = 0x03000201;         int  buffer2= 0x010203;         file = fopen("test.bin", "wb");          if (file != null)         {                 fwrite(&buffer, sizeof(buffer), 1, file);                 fwrite(&buffer2, sizeof(buffer2), 1, file);                 fclose(file);         }          return 0; } 

and continues until loop over, iterating through bytes of data. how possible?

use struct module, allow interpret binary data in many ways; need define types in string format documented library:

struct.unpack('=hhf255s', bytes) 

the above example expects native byte-order, 2 unsigned shorts, float , string of 255 characters.

your code example becomes:

for each_word in logdata:     var1, var2, var3 = struct.unpack('8s16s8s', each_word) 

in case error typeerror: 'str' not support buffer interface, because bytes expected, passed str, convert bytes , specify encoding (in example, utf-8):

for each_word in logdata:     var1, var2, var3 = struct.unpack('8s16s8s', bytes(each_word, 'utf-8')) 

but maybe case 8/16 byte strings long integers? in case use appropriate format struct.

edit: turns out wanted read 8 bits (not bytes), next 16 bits, next 8 bits, can read 1 (unsigned?) byte, 1 short, , byte. format string should use '=bhb' (or '=bhb' unsigned). example:

import struct open('test.bin','rb') f:     var1, var2, var3 = struct.unpack('=bhb', f.read(4))     print(var1, var2, var3)