with open("bin-file", "rb") as f:
for line in f:
    # Here I deal with every line

import struct
unpack_str = '=?iiiiiiii...' # The actual string contains 739 i's
n_bytes = 2957 # There are 2957 bytes per line

with open("bin-file", "rb") as f:
    line_bin = f.read(n_bytes)
    line_str = struct.unpack(unpack_str,line_bin)