Efficiently reading structured binary files using numpy’s fromfile method

nev_packet = pylab.dtype([    (‘nstx’, ‘h’),    (‘npkt_id’, ‘h’),    (‘npkt_data_size’, ‘h’),    (‘timestamp’, ‘Q’),    (‘eventid’, ‘h’),    (‘nttl’, ‘H’),    (‘ncrc’, ‘h’),    (‘ndummy1’, ‘h’),    (‘ndummy2’, ‘h’),    (‘dnExtra’, ‘8i’),    (‘eventstring’, ‘128c’)  ])  data = pylab.fromfile(fin, dtype=nev_packet, count=-1)

Using -1 to indicate "upto the end"

I was writing some code in Python to read a binary file, extract packets of information and write out subsets of information to different files. The code was, in essence, this: def func(f, max_packets=-1,buffer_len=100):    if buffer_len < max_packets:       buffer_len = max_packets     d = f.read(buffer_len)    while len(d):       #Process       d = f.read(buffer_len) There was… Read More Using -1 to indicate "upto the end"