How to loop over a binary file in Python in chunks

Question

I\'m trying to use Python to loop over a long binary file filled with 8-byte records.

Each record has the format [ uint16 | uint16 | uint32 ]
(which

Answer 1

f.read(len) only returns a byte string. Then raw will be a single byte.

The correct way of looping is:

with open(fname, 'rb') as f:
    while True:
        raw = f.read(8)
        if len(raw)!=8:
            break # ignore the incomplete "record" if any
        record = struct.unpack("HHI", raw )
        print(record)