Native Messaging: Python programme executes all lines but does not run any 'subprocess.Popen()' lines

[hans_squared]

The subprocess module documentation says:

The recommended approach to invoking subprocesses is to use the run() function for all use cases it can handle. For more advanced use cases, the underlying Popen interface can be used directly.

Real Python has a tutorial on the subprocess module:

The subprocess Module: Wrapping Programs With Python – Real Python

But I can’t tell you if it’s any good, because I haven’t read it yet…