Read an "input.bag" ROS bag with messages stored in arbitrary order, and write to "output.bag" ordered by receive time (required by Webviz to read)

reorder-rosbag.py

import rosbag

with rosbag.Bag('output.bag', 'w') as outbag:
    for topic, msg, t in rosbag.Bag('input.bag').read_messages():
        outbag.write(topic, msg, t)