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ImportError: No module named 'em', Error

asked 2017-03-23 22:59:24 -0600

tomcattiger gravatar image


I create a test package as tutorial using

catkin_create_pkg beginner_tutorials std_msgs rospy roscpp.

When I add a custom message, it comes error

[100%] Built target beginner_tutorials_generate_messages_lisp

Traceback (most recent call last):

File "/opt/ros/kinetic/share/gencpp/cmake/../../../lib/gencpp/", line 41, in <module>

import genmsg.template_tools

File "/opt/ros/kinetic/lib/python2.7/dist-packages/genmsg/", line 39, in <module>

import em

ImportError: No module named 'em'

beginner_tutorials/CMakeFiles/beginner_tutorials_generate_messages_cpp.dir/build.make:62: recipe for target '/home/arnoldx201/catkin_ws/devel/include/beginner_tutorials/Complex.h' failed

make[2]: * [/home/arnoldx201/catkin_ws/devel/include/beginner_tutorials/Complex.h] Error 1 CMakeFiles/Makefile2:1136: recipe for target 'beginner_tutorials/CMakeFiles/beginner_tutorials_generate_messages_cpp.dir/all' failed

make[1]: * [beginner_tutorials/CMakeFiles/beginner_tutorials_generate_messages_cpp.dir/all] Error 2

Makefile:138: recipe for target 'all' failed

make: * [all] Error 2

Invoking "make -j4 -l4" failed

When I use directly python --> import cm, there is no problem.

Has anyone met the same problem before? Thanks

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Hattest du eine Lösung für dein Problem gefunden?

Ich stehe momentan vor dem exakt gleichen Problem und komme nicht weiter :(

fettespferd gravatar image fettespferd  ( 2019-01-21 06:49:08 -0600 )edit

2 Answers

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answered 2017-03-24 00:14:07 -0600

ahendrix gravatar image

Yes, other users have seen this before.

A quick search on this site for the title of your question turns us: , and , all of which describe different causes for this error and possible solutions.

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I had this same problem. The first link had the solution that solved it for me. I needed to install the python empy library. "pip install empy" and then "catkin_make" worked. Thanks!

mkelly66 gravatar image mkelly66  ( 2019-07-22 22:42:02 -0600 )edit

answered 2019-12-11 00:22:53 -0600

bobo_truth gravatar image

I have fixed this by running sudo apt-get install python3-empy

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worked for me too :)

Lidor Shimoni gravatar image Lidor Shimoni  ( 2020-01-27 06:32:14 -0600 )edit

Worked for me too. THanks BUddy

Deepak_Kr_Yadav gravatar image Deepak_Kr_Yadav  ( 2020-02-21 08:24:47 -0600 )edit

Thank You. After many tried, the 'sudo apt-get install python3-empy' works.

Morna_Bot gravatar image Morna_Bot  ( 2020-05-18 03:38:47 -0600 )edit

Thank you! This solved the problem.

jlpm gravatar image jlpm  ( 2020-06-11 16:28:42 -0600 )edit

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Asked: 2017-03-23 22:59:24 -0600

Seen: 17,135 times

Last updated: Mar 24 '17