rosbag_to_csv_example.py

#!/usr/bin/env python3
import argparse
import csv
import datetime
import math

import rosbag


parser = argparse.ArgumentParser()
parser.add_argument('--topic')
parser.add_argument('--every', type=int, default=1)
parser.add_argument('input')
parser.add_argument('output')
args = parser.parse_args()


bag = rosbag.Bag(args.input)
writer = csv.writer(open(args.output, 'w', newline=''))

# Write the header row
writer.writerow(('time', 'value'))


i = -1
for topic, msg, t in bag:
    if topic == args.topic:
        i += 1
        if i % args.every != 0:
            continue

        ts = datetime.datetime.utcfromtimestamp(t.to_sec())

        writer.writerow((
            ts.isoformat(),
            msg.data
        ))