Can you post some information about your problem? To help you we'd need to see the exact error and your CMakeLists.txt and package.xml

Thanks.

My package.xml (besides comments):

catkin message_generation message_runtime

My CMakeLists.txt(the places where I made changes):

find_package(catkin REQUIRED COMPONENTS std.msgs message_generation )

add_message_files( FILES Robotjon.msg )

generate_messages( DEPENDENCIES std_msgs
)

catkin_package(

CATKIN_DEPENDS message_runtime

)

My python code:

! /usr/bin/env python

import rospy

from mode_publishers.msg import Robotjon

rospy.init_node('topic_publisher') pub = rospy.Publisher('/topic_ex', Robotjon, queue_size=1) rate=rospy.Rate(2) message = Robotjon() message.custom_msg = "Hello World"

while not rospy.is_shutdown(): pub.publish(message) rate.sleep()

My Robotjon.msg:

string custom_msg

My Robotjon.msg file is inside the mode_publishers package

I don't see anything obviously wrong with the snippets you've posted. Here's some things to check: 1. Is Robotjon.msg in the mode_publishers/msg directory. 2. Are there any spelling mistakes? Maybe an extra _ or an i instead of a j? 3. Do you get any errors when you run catkin_make? 4. Does the package name in the package.xml file match the package name in the CMakeLists.txt? 5. After you source devel/setup.bash what do you have in your PYTHONPATH environment variable? Does mode_publishers show up?

1. Yes, Robotjon is in the mode_publishers/msg directory.
2. No,everything is true. It is j, not i
3. No errors during catkin_make. But one thing I noticed. In the youtube videos, when they did catkin_make, they got something with percentages. 10%, 20%, ..... 100% accomplished. In my case, there were not such percentages in my terminal during compiling.
4. Yes, they match: everywhere it is mode_publishers
5. Let me check...

When I am running rosmsg show Robotjon:

mode_publishers/Robotjon:
string custom_msg

I think everything is ok

BUT During running catkin_make I noticed that there are no such messages in my terminal during compiling like in youtube videos:

[16%] BUILT TARGET <name of package>_generate_messages Scanning dependencies..... [33%] BUILT TARGET <name of package>_generate_messages Scanning dependencies..... [50%] BUILT TARGET <name of package>_generate_messages Scanning dependencies..... [66%] BUILT TARGET <name of package>_generate_messages Scanning dependencies..... [83%] BUILT TARGET <name of package>_generate_messages Scanning dependencies..... [100%] BUILT TARGET <name of package>_generate_messages Scanning dependencies.....

@Nurbek can you please update your question with this information (code, package.xml, CMakelists.txt, terminal output)? Having this information in the comments in the comments makes your question difficult to follow.

Also, did you source your setup.bash file? I.e., run

source devel/setup.bash

from the root of your workspace?

Yes, I did

Two other simple things that could go wrong:

1. Do you run your python script in the same terminal that you ran source devel/setup.bash
2. Which version of python do you get when you run the python command? If if is python 3, try running your script using python 2 instead.

If that isn't it, it seems likely that something is going wrong with your build, so it might help to see the build output.

What should happen when you run catkin_make is that a Robotjon.py file is generated in a sub-directory of the devel directory in your workspace (sorry I don't remember the exact path off hand. It'll be something like devel/share/lib/mode_publishers/msg/Robotjon.py). When you sourcedevel/setup.bash` that path to your package should be added to the PYTHON_PATH environment variable.

So if the file is not there, please post your complete CMakeLists.txt and your build output because that's where the problem probably lies.

Updating your question with the information in these comments (e.g., the code, package.xml, etc) so that it's formatted and easy to read and follow will also go a long way to getting your question answered.

Thank you! I created a new workspace and tried everything from the beginning. Now it works.

The problem is that I used "old" created workspace and there could be some errors