Highlevel APIs

The rosbags.highlevel package provides classes that abstract the complexity of ROS types, serialization and message access into single easy-to-use interfaces.

All in one reader

Instances of the AnyReader class give unified access to ROS1 and ROS2 bag files. If a bag file includes message definitions the reader auto-registers all messages into a blank type store, otherwise it falls back to the default type store. It also exposes appropriate deserialization methods on the reader instance itself.

from pathlib import Path

from rosbags.highlevel import AnyReader

# create reader instance and open for reading
with AnyReader([Path('/home/ros/rosbag_2020_03_24')]) as reader:
    connections = [x for x in reader.connections if x.topic == '/imu_raw/Imu']
    for connection, timestamp, rawdata in reader.messages(connections=connections):
         msg = reader.deserialize(rawdata, connection.msgtype)
         print(msg.header.frame_id)

AnyReader takes a list of pathlib.Path instances as arguments. It can take either one ROS2 bag file or one or more ROS1 bag files belonging to a split bag. The reader will replay ROS1 split bags in correct timestamp order.