Is there a way to save all rosbag data into a .csv or text file ?

edit

Here's a quick way:

rosbag play mybag.bag
rostopic echo /foo > output.txt

This will output all message in the topic /foo to a yaml-formatted text file. You can then parse the file. It might be useful to output to multiple files for different fields. Let's say the message type on /foo is Pose:

rosbag play mybag.bag
rostopic echo /foo/position/x > output_x.txt
rostopic echo /foo/position/y > output_y.txt
rostopic echo /foo/position/z > output_z.txt

You can also look into bagys, which are an extension of the concept above.

Please see this answer for a simple script to save all topics in the bag file as a seperate csv.

Please let me know if you found this useful or if you have any suggestions for how to improve it.

A more flexible way of doing this could be with Pandas. After you record your data, you can sift through it to gather the information you need, add it to a dataframe, perform any operations on it, and save it to a .csv. For example, lets consider some points.

import rosbag
from geometry_msgs.msg import Point
import pandas as pd

# The bag file should be in the same directory as your terminal
bag = rosbag.Bag('./recorded-data.bag')
topic = '/your_topic'
column_names = ['x', 'y']
df = pd.DataFrame(columns=column_names)

for topic, msg, t in bag.read_messages(topics=topic):
    x = msg.x
    y = msg.y

    df = df.append(
        {'x': x,
         'y': y},
        ignore_index=True
    )

df.to_csv('out.csv')

Take a look for this package which provide a GUI interface to convert topics into csv -> rosbag_to_csv