Joins rosbags that are in chronological order into a single bagfile.

join_bags.py

#! /usr/bin/python3

import sys
from pathlib import Path

import rosbag
from tqdm import tqdm


def main():
    # Read the name of bagfiles from the command line args
    # Merge the bags and create a new bagfile output
    
    if len(sys.argv) < 3:
        print("Usage: join_bags.py bag1 bag2 [bagn...] <output>")
        sys.exit(1)
        
    bagfiles = sys.argv[1:-1]
    output = sys.argv[-1]
    
    for file in bagfiles:
        if not Path(file).is_file():
            print(f"File {file} not found")
            sys.exit(1)
            
    if Path(output).is_file():
        print(f"File {output} already exists")
        sys.exit(1)
        
    
    print("Starting Merge")
    with rosbag.Bag(output, 'w') as outbag:
        for bagfile in tqdm(bagfiles, unit="bags"):
            with rosbag.Bag(bagfile, 'r') as inbag:
                for topic, msg, t in tqdm(inbag.read_messages(), total=inbag.get_message_count(), unit="msgs"):
                    outbag.write(topic, msg, t)
                    
    print("Done")

if __name__ == '__main__':
    main()