Out-of-Process Execution of Python Functionality
There is overhead associated with calling Python® functions out-of-process. This behavior affects performance. MathWorks recommends calling Python functions in-process, which is the default mode.
MATLAB® can run Python scripts and functions in a separate process. Running Python in a separate process enables you to:
Use some third-party libraries in the Python code that are not compatible with MATLAB.
Isolate the MATLAB process from crashes in the Python code.
To run out-of-process, call the
"ExecutionMode" argument set to
For example, suppose that you want to create this
list variable in the
['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday']
To create this
list out-of-process, set the MATLAB execution mode to
"OutOfProcess". MATLAB displays information about your current Python environment.
ans = PythonEnvironment with properties: Version: "2.7" Executable: "C:\Python27\pythonw.exe" Library: "C:\windows\system32\python27.dll" Home: "C:\Python27" Status: NotLoaded ExecutionMode: OutOfProcess
Create the variable.
ans = Python list with no properties. ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday']
MATLAB creates a process named
ans = PythonEnvironment with properties: Version: "2.7" Executable: "C:\Python27\pythonw.exe" Library: "C:\windows\system32\python27.dll" Home: "C:\Python27" Status: Loaded ExecutionMode: OutOfProcess ProcessID: "8196" ProcessName: "MATLABPyHost"
Clearing a Python object is asynchronous, which means that the Python object might remain in Python after the invocation of a synchronous call. For example, in the following code it
is possible that
myList2 is created before
myList=py.list; clear myList myList2 = py.list;
The size of variables passed between Python and MATLAB is limited to 2 GB when you call a Python function out-of-process. This limit applies to the data plus supporting information passed between the processes.