from struct import Struct
def write_records(records, format, f):
record_struct = Struct(format)
for r in records:
f.write(record_struct.pack(*r))
def unpack_records(format, data):
record_struct = Struct(format)
return (record_struct.unpack_from(data, offset) for offset in range(0, len(data), record_struct.size))
if __name__ == '__main__':
records = [(1, 2.3, 4.5),
(6, 7.8, 9.0),
(12, 13.4, 56.7)]
with open('data.b', 'wb') as f:
write_records(records, '<idd', f)
from collections import namedtuple
Record = namedtuple('Record', ['kind', 'x', 'y'])
with open('data.b', 'rb') as f:
data = f.read()
for rec in unpack_records('<idd', data):
record = Record(*rec)
print(record)
Record(kind=1, x=2.3, y=4.5)
Record(kind=6, x=7.8, y=9.0)
Record(kind=12, x=13.4, y=56.7)
