class_method_exception_simulation_decorator.py

from functools import wraps


def allow_simulate_exception(exception_class=Exception):
    def _allow_simulate_exception(method):
        """Decorator that allows to raise an exception """

        @wraps(method)
        def _raise_exception_if_method_name_fits(self, *method_args,
                                                 **method_kwargs):
            if method.__qualname__.split('.')[-1] == self.raise_exception_in_method:
                raise exception_class(
                    f'Simulated exception in method '
                    f'{self.raise_exception_in_method}.')
            method_output = method(self, *method_args, **method_kwargs)
            return method_output

        return _raise_exception_if_method_name_fits
    return _allow_simulate_exception


class Foo:
    
    def __init__(self, raise_exception_in_method=None):
        self.raise_exception_in_method = raise_exception_in_method
    
    @allow_simulate_exception(RuntimeError)
    def bar(self, print_this='hello'):
        print(print_this)

        
foo_no_exception = Foo()
foo_no_exception.bar()

foo_with_exception = Foo(raise_exception_in_method='bar')
foo_with_exception.bar()