Using JuliaPy/PyJulia to interconnect with MATLAB

[asavasci]

Hi all. I appreciate the efforts to improve Python<-> Julia interconnection. I am using Julia 1.6.1 and Python 3.8.8 (not anaconda installation) on Windows. The interconnection is working very well.
I am able to call both core Julia and my own Julia functions within the Python terminal. Up to this point, everything is fine.

However, I am also trying to interconnect Julia --> MATLAB by means of Python because of the lack of a mature Matlab<->Julia interface, yet. This is working only if I use Julia's core functions inside my own function as following

function makeupper_byjulia(str_in)     # placed in a file "juliaFunctionLib.jl"
  return uppercase(str_in)
end

within Python terminal I use the above Julia function by first importing the Python function below from "juliaLibInterface.py"

def makeupper(word):   # placed in a file "juliaLibInterface.py"
    import julia 
    from julia import Main
    Main.include("juliaFunctionLib.jl")
    return Main.makeupper_byjulia(word)

MATLAB returns expected output in prompt when I type py.juliaLibInterface.makeupper('somestring')

When I call a Julia function which also includes other functions from Julia Modules such as DataFrames, JuMP, etc. MATLAB raises an error message as

Error using py.juliaLibInterface.function_xyz
Cannot find class 'py.PyCall.jlwrap'.

How can I resolve this issue?

[tkf]

Hmm... not sure what MATLAB tries to do, but I wonder if you can create a file PyCall.py (say, in the current directory) like this

from julia import Main
sample = Main.eval("""
        struct Dummy
        end
        Dummy()
""")
jlwrap = type(sample)

and see if it can convince MATLAB that PyCall.jlwrap is a legit type. It's a horrible hack but maybe we can automate this.