How to load .mat file into workspace using Matlab Engine API for python?

I have a .mat workspace file containing 4 character variables. These variables contain paths to various folders I need to be able to cd to and from relatively quickly. Usually, when using only Matlab I can load this workspace as follows (provided the .mat file is in the current directory).

    load paths.mat

Currently I am experimenting with the Matlab Engine API for python. The Matlab [help docs][1] recommend using the following python formula to send variables to the current workspace in the desktop app:

    import matlab.engine
    eng = matlab.engine.start_matlab()
    x = 4.0
    eng.workspace['y'] = x
    a = eng.eval('sqrt(y)')
    print(a)

Which works well. However the whole point of the .mat file is that it can quickly load entire *sets*** of variables the user is comfortable with. So the above is not efficient when trying to load the workspace.

I have also tried two different variations in Python:

    eng.load("paths.mat")
    eng.eval("load paths.mat")

The first variation successfully loads a dict variable in python containing all four keys and values but this does not propagate to the workspace in Matlab. The second variation throws an error:

> File "<string>", line unknown SyntaxError: Error: Unexpected MATLAB > expression.

How do I load up a workspace through the engine without having to manually do it in Matlab? This is an important part of my workflow....

[1]: https://nl.mathworks.com/help/matlab/matlab_external/use-the-matlab-engine-workspace-in-python.html

Answer 1

[J Philps]

There are two things you may want to try:

1. use the function syntax (not command syntax) for load:

eng.eval("load('paths.mat')")

Note: you may need to escape the ' characters above, like so:

eng.eval("load(\'paths.mat\')")

2. I would try using single quotes:

eng.load('paths.mat')

There is a distinction between "string objects" and 'character arrays' in MATLAB, so that error message about strings may be related to this.