Exception handling for Azure Durable Functions in Python

durable-functions-handle-exception.py

    try:
        # Orchestration code here...
    except Exception as e:
        # Any exception that is raised by a function is re-raised by its enclosing 
        # activity task. The original error message is part of the new exception
        # message, formatted as "Activity function '<function_name>' failed:  
        # <exception_type>: <exception_message>", so a regex is used to extract the
        # original message and generate a friendlier output.
        function_name = None
        function_exception_type = None
        function_exception_msg = None
        activity_exception_msg = ''.join(e.args)
        activity_exception_matcher = re.search(
            r"Activity[\s]*function[\s]*'(?P<function_name>.+?)'[\s]*failed:"
            r"[\s]*(?P<exception_type>.+?):"
            r"[\s]*(?P<exception_message>.+?)[\s]*\n", activity_exception_msg)

        if activity_exception_matcher:
            function_name = activity_exception_matcher.group('function_name')
            function_exception_type = \
                activity_exception_matcher.group('exception_type')
            function_exception_msg = \
                activity_exception_matcher.group('exception_message')
            context.set_custom_status(function_exception_msg)

        orchestrator_msg = f"'{function_name}' raised {function_exception_type} >> " \
                           f" {function_exception_msg}'" \
                           if function_exception_msg else activity_exception_msg
        output.append(orchestrator_msg)
        raise Exception(output)