import metric_pb2

from google.protobuf.internal.encoder import _VarintBytes

from google.protobuf.internal.decoder import _DecodeVarint32

with open('out.bin', 'wb') as f:

for i in range(128):

my_metric = metric_pb2.Metric()

my_metric.name = 'sys.cpu'

my_metric.type = 'gauge'

my_metric.value = i

my_metric.tags = str(i) + 'tag'

size = my_metric.ByteSize()

f.write(_VarintBytes(size))

f.write(my_metric.SerializeToString())

with open('out.bin', 'rb') as f:

buf = f.read()

n = 0

while n < len(buf):

msg_len, new_pos = _DecodeVarint32(buf, n)

n = new_pos

msg_buf = buf[n:n+msg_len]

n += msg_len

read_metric = metric_pb2.Metric()

read_metric.ParseFromString(msg_buf)

# do something with read_metric

print(read_metric)