caffe_lmdb.py 文件源码

def loop_records(self, num_records=0, init_key=None):
        env = lmdb.open(self.fn, readonly=True)
        datum = Datum()
        with env.begin() as txn:
            cursor = txn.cursor()
            if init_key is not None:
                if not cursor.set_key(init_key):
                    raise ValueError('key ' + init_key + ' not found in lmdb ' + self.fn + '.')

            num_read = 0
            for key, value in cursor:
                datum.ParseFromString(value)
                label = datum.label
                data = datum_to_array(datum).squeeze()
                yield (data, label, key)
                num_read += 1
                if num_records != 0 and num_read == num_records:
                    break
        env.close()