read bag messages as numpy in python [closed]

asked 2012-10-29 13:05:36 -0500

Eruditass gravatar image

updated 2014-01-28 17:14:06 -0500

ngrennan gravatar image

I see how to subscribe to a message to get arrays as numpy arrays, but is there a way to read from a bag file and get numpy arrays?

This does not work:

import rosbag
bag = rosbag.Bag('bag.bag')
from rospy.numpy_msg import numpy_msg

msgs = bag.read_messages(topics=['blah'])
msg = numpy_msg(

TypeError: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases

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Closed for the following reason question is not relevant or outdated by tfoote
close date 2015-09-18 18:45:05.816621



Why is this question closed? @tfoote. I have this problem, and would like a solution

eric-wieser gravatar image eric-wieser  ( 2016-03-16 15:49:29 -0500 )edit

for topic, msg_raw, t in bag.read_messages(raw=True):

         msg_type = msg_raw[4]
         msg = msg_type()
         msg.deserialize_numpy(msg_raw[1], numpy)`
afakih gravatar image afakih  ( 2017-02-07 14:58:54 -0500 )edit

Hey @afakih, your comment was somewhat hint for me. thnx

Braad gravatar image Braad  ( 2017-12-27 05:50:35 -0500 )edit