pyobjc-framework-exceptionhandling

import objc from Foundation import NSObject, NSLog # Enable verbose logging for PyObjC to see detailed stack traces # when exceptions cross the Python/Objective-C boundary. # This is key for understanding issues related to ExceptionHandling. objc.setVerbose(True) class MyPythonException(Exception): """A custom Python exception to demonstrate bridging.""" pass # Define an Objective-C class (via Python subclassing NSObject) class MyObjCClass(NSObject): def init(self): self = super().init() if self: NSLog("MyObjCClass initialized in Python") return self def triggerPythonException_(self, arg): """An Objective-C callable method that might raise a Python exception.""" NSLog("Objective-C calling Python method to trigger exception with arg: %@", arg) if arg == "error": raise MyPythonException("An error occurred in Python!") return "Python successfully processed: " + arg if __name__ == "__main__": obj = MyObjCClass.alloc().init() # Example 1: Call method that triggers a Python exception print("\n--- Attempting to trigger an exception ---") try: # When Python raises an exception, PyObjC translates it into an # Objective-C exception. If caught back in Python, it manifests as objc.error. result = obj.triggerPythonException_("error") print(f"Result (should not be reached): {result}") except objc.error as e: print(f"Caught Objective-C error (originally Python exception): {e}") except MyPythonException as e: # This would not be caught directly here print(f"Caught Python exception directly: {e}") # Example 2: Call method that succeeds print("\n--- Attempting a successful call ---") result = obj.triggerPythonException_("success") print(f"Successful call result: {result}")