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I was following the tutorial WrittingServiceClient(Python). I have typed the code as it is. The project "makes" properly also, but when I try to rosrun the server or the client the following error shows:
from beginner_tutorials import * ImportError: No module named srv
Where am I going wrong? How to create the module srv?
N.B.: I have followed the tutorial "Creating a ROS msg and srv" and the srv file exists inside the beginner_tutorials/srv
I had this error because of module name conflict.
e.g.:
catkin_ws/
| src/
| package/
| srv/
| service.srv
| scripts
| package.py
| code_using_service.py
I was importing the service into the code_using_service.py file and got the error message:
from package.srv import *
ImportError: No module named srv
It was looking for the srv module inside my package.py module instead of inside my package/ module. So I just renamed my script file to package_node.py to avoid the conflict.
Service name and package name can be the same, right?
In the tutorial Writing a Simple Service and Client (Python), do Build your nodes section and rosrun again. It seems to me you might not have generated *.srv modules. In that tutorial page, don't forget to choose your build system (if you're using rosmake, choose rosbuild).
The module srv is a python module, which in practice just means a folder named srv with a __init__.py in it. This file is generated from .srv files you define, when building the project correctly.
With catkin, the safest way to rebuild everything is to delete your build and devel folders and rebuild everything.
I don't think this is an answer. You can remove those folders and rebuild everything, there is no guarantee that it will work. One has to check CMakeLists.txt, package.xml and the code files, all should be consistent with the package name and all that.
I had the same problem. It turned out I had forgotten to uncomment this part of my CMakeLists.txt:
add_service_files( FILES AddTwoInts.srv )
i had same problem , I had to source the( devel/setup.bash) in each instance of web shell I was calling the scripts from. Once for the client, once for the server. Then, it worked
Asked: 2013-01-19 04:22:11 -0500
Seen: 17,110 times
Last updated: Aug 01 '16
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Did you sort it out? I am having exactly the same problem...
I encounter the same problem right now, has anybody found why it happens ?
In my case, I had to
sourcethedevel/setup.bashin each instance of the console I was calling the scripts from. Once for the client, once for the server. Then, it worked for me.