About the Python path in the package



I am using MichiganAutonomousVehicles package. I have successfully installed it. But I am now facing the problem when using MichiganAutonomousVehicles.

ERROR: InitError: PyError (PyImport_ImportModule

The Python package rospy could not be found by pyimport. Usually this means
that you did not install rospy in the Python version being used by PyCall.

PyCall is currently configured to use the Python version at:


and you should use whatever mechanism you usually use (apt-get, pip, conda,
etcetera) to install the Python package containing the rospy module.

One alternative is to re-configure PyCall to use a different Python
version on your system: set ENV[“PYTHON”] to the path/name of the python
executable you want to use, run Pkg.build(“PyCall”), and re-launch Julia.

Another alternative is to configure PyCall to use a Julia-specific Python
distribution via the Conda.jl package (which installs a private Anaconda
Python distribution), which has the advantage that packages can be installed
and kept up-to-date via Julia. As explained in the PyCall documentation,
set ENV[“PYTHON”]="", run Pkg.build(“PyCall”), and re-launch Julia. Then,
To install the rospy module, you can use pyimport_conda("rospy", PKG),
where PKG is the Anaconda package the contains the module rospy,
or alternatively you can use the Conda package directly (via
using Conda followed by Conda.add etcetera).

I met this problem in Windows and I can’t fix by downloading Anaconda.


Do you install rospy? What is the Python executable in which you can import rospy? Looking at http://wiki.ros.org/melodic/Installation, https://github.com/JuliaMPC/MichiganAutonomousVehicles.jl/issues/8, https://answers.ros.org/question/259437/how-to-run-ros-if-your-default-python-version-is-3x-via-anaconda/, etc., it looks like rospy is required to be installed in a non-standard way.


I installed it and there’s no problem now! Thank you!