Update: I can't use this workflow if I pass a variable into reloadPy because clear classes will delete the variable. I have also submitted a support ticket.
How can I clear specific Python classes/modules from memory without using "clear classes"
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I have successfully developed a workflow that will allow me to call custom python code from Matlab, see the following two scripts:
MATLAB:
function out = reloadPy() % A Matlab function
clear classes
mod = py.importlib.import_module('mymod');
py.importlib.reload(mod);
v1 = 1:5;
v2 = 6:10;
out = double(py.mymod.add2Vectors(v1,v2));
Python:
# mymod.py - a python function
import numpy
import array
def add2Vectors(v1, v2):
myarray = numpy.array(v1) + numpy.array(v2)
return array.array('d', myarray)
If I call reloadPy from the command line I get the following output:
>> test = reloadPy
Warning: Objects of 'onCleanup' class exist. Cannot clear this class or any of its superclasses.
> In reloadPy (line 2)
Warning: Objects of 'table' class exist. Cannot clear this class or any of its superclasses.
> In reloadPy (line 2)
Warning: Objects of 'datetime' class exist. Cannot clear this class or any of its superclasses.
> In reloadPy (line 2)
test =
7 9 11 13 15
>>
The warnings are stemming from the "clear classes" command. I am using that sequence of commands (lines 2-4) to reload the python module while debugging. Any changes I make to mymod.py are not captured unless I execute all 3 commands. The documentation for "clear" states:
Calling clear all, clear classes, and clear functions decreases code performance, and is usually unnecessary. ...
To clear a particular class, use clear myClass.
Is there a way to just clear just my python class or module? I can't find the name. I tried
[M, X, C] = inmem
But none of the result seem to be related to python.
Answers (2)
Emil Geiger
on 19 Jul 2018
2 Comments
Minchae Jeong
on 25 Nov 2021
Edited: Minchae Jeong
on 25 Nov 2021
Love you my brother this helped me a lot!
Arwel
on 5 Mar 2024
Thanks Emil! This also worked for me, and this makes it general for my use-case (via a file)....
function reloadPy(name)
% Save the module name (so we can reload it after clear..)
save('tempSave','name');
warning('off','MATLAB:ClassInstanceExists')
clear classes
% Reload the name....
name = load('tempSave');
name = name.name;
% Now reload the module....
mod = py.importlib.import_module(name);
py.importlib.reload(mod);
% Get rid of our temporary file...
delete('tempSave.mat');
Fan Yang
on 20 Jun 2022
Say, if we want to reload 'util.py':
py.util = py.importlib.reload(py.importlib.import_module('util'));
This line would work for me. It actually redefined a struct with name 'py', so it may overwrite other module you imported, but if all of your python module is explicitly imported in this way, there seems to be no problem. Anyway this should be regarded as a workaround as well.
3 Comments
Lucademicus
on 8 Dec 2023
It does not work for me in 2023B. Does anyone have another solution for me?
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