[SOLVED] Python Binary File Read and Parse

Hi to everyone , i have a challenge right now in python that for now needs a bit of help in one part of the c0de.
The task is create a new file with the name of the file defined by the ASCII content between the 3 byte and the 16 byte that is parsed from the binary file, the file is over 20 Mb i need to create a file for each record ( each record contains the len of 820 ), so right now i know how to read it and do something with it, like :

Code:

Code:

#!/usr/bin/python

with open("file", "rb") as f:
	byte = f.read()
	if byte > 820:
	    print "Reach the 1 record mark on the File you have defined "

#attention noob code coming for quick understading i have a for loop for #example not for use i have to use it for the each 820 bytes new file
#with the read of the 820 bytes on the new file and save it and go for the
#next 820 bytes and so on until the end of the file.
for f.read(820) in file:
    if f.read() = 820:
       a = f.read()
       b = open("Iam_from_2_to_16_byte_string", w)
       b.write(a)
       b.close

n = 820
with open('/home/drdos/work/file.PDA', "rb") as f:
    while True:
        data = f.read(n)
        if not data:
            break
        
        filename = str(data[16:32])
        
        x = open(filename, 'wb').write(data)