AttributeError: 'numpy.ndarray' object has no attribute 'get_fields_and_field_types'

[Miker2808]

When attempting to run with my rosbag I generated from a simulation I received this error, tried both in ubuntu 20 and windows 10
Working on ROS2 Foxy.

`
['/simulation/d9/gps', '/simulation/d9/imu/acceleration', '/simulation/d9/imu/orientation', '/simulation/d9/imu/orientation/rate', '/simulation/d9/imu/velocity']
Traceback (most recent call last):
File "/home/simteam/.local/bin/ros2bag-convert", line 8, in
sys.exit(main())
File "/home/simteam/.local/lib/python3.8/site-packages/ros2bag_convert/main.py", line 14, in main
data = read_bag.read_from_all_topics(file_url,True)
File "/home/simteam/.local/lib/python3.8/site-packages/ros2bag_convert/ros2bag_convert/read_bag.py", line 210, in read_from_all_topics
timestamps, messages = read_from_topic(bag_file, topic_names[i], print_out)
File "/home/simteam/.local/lib/python3.8/site-packages/ros2bag_convert/ros2bag_convert/read_bag.py", line 183, in read_from_topic
dic_data = message_converter.convert_ros_message_to_dictionary(msg)
File "/home/simteam/.local/lib/python3.8/site-packages/ros2bag_convert/ros2bag_convert/message_converter.py", line 243, in convert_ros_message_to_dictionary
dictionary[field_name] = _convert_from_ros_type(field_type, field_value)
File "/home/simteam/.local/lib/python3.8/site-packages/ros2bag_convert/ros2bag_convert/message_converter.py", line 259, in _convert_from_ros_type
field_value = convert_ros_message_to_dictionary(field_value)
File "/home/simteam/.local/lib/python3.8/site-packages/ros2bag_convert/ros2bag_convert/message_converter.py", line 240, in convert_ros_message_to_dictionary
message_fields = message.get_fields_and_field_types()
AttributeError: 'numpy.ndarray' object has no attribute 'get_fields_and_field_types'

`

[ferasterkawi]

The same problem. Did you find a solution?

[Miker2808]

Afraid I did not, decided to use a solution that doesn't require ros2 bag.
from my digging it seems related to the code screwing up with "rosidl" somewhere

[MarioAlmelaUMH]

Even after the merging, I'm still getting this error. Has anyone made any more advances?

Tank you very much.

[FeiduoduoPeng]

Did you guys finish the probelem?

[andrewTianxiaolu]

Guys this problem is caused by the "message_conventer.py". Here is the resolution of this problem:
mehmetkillioglu/ros2_message_converter#3 (comment)

def _is_ros_binary_type(field_type):
""" Checks if the field is a binary array one, fixed size or not
list(bytearray(de(encoded_data)))
_is_ros_binary_type("uint8")
>>> False
_is_ros_binary_type("uint8[]")
>>> True
_is_ros_binary_type("uint8[3]")
>>> True
_is_ros_binary_type("char")
>>> False
_is_ros_binary_type("char[]")
>>> True
_is_ros_binary_type("char[3]")
>>> True
_is_ros_binary_type("octet")
>>> True
"""
return field_type.startswith('uint8[') or field_type.startswith('char[') or field_type.startswith('octet')

Add the octet type here.

[MarioAlmelaUMH]

Hi. I've added the octet type:

However, I'm still getting a similar error:

I'm using a whole bunch of custom message types, so I wonder if I should add more clauses besides uint8, char and octet. Do you know how can I check which ones to add?

Thank you in advance.

[gcgloven]

you can try modify the convert_ros_message_to_dictionary function to:

def convert_ros_message_to_dictionary(message):
    """
    Takes in a ROS message and returns a Python dictionary.

    Example:
        ros_message = std_msgs.msg.String(data="Hello, Robot")
        dict_message = convert_ros_message_to_dictionary(ros_message)
    """
    dictionary = {}
    if hasattr(message, 'get_fields_and_field_types'):
        message_fields = message.get_fields_and_field_types()
        for (field_name, field_type) in message_fields.items():
            field_value = getattr(message, field_name)
            dictionary[field_name] = _convert_from_ros_type(field_type, field_value)
    else:
        dictionary = None

    return dictionary

Also, add create csv if not exist function to save_csv_file.py:

def save_csv_file(data, csv_file_name, version=0, print_out=False):
    """ Save data to a csv_file_name (use it after 'read_from_all_topics').
    """

    # Create csv file
    import os

    if not os.path.exists(os.path.dirname(csv_file_name)):
        os.makedirs(os.path.dirname(csv_file_name))

    ...................................

[lidarmansiwon]

This is a package that modified the code based on the above advice. You can use git clone as it is.

https://github.com/lidarmansiwon/ros2bag_convert_foxy