我正在阅读这篇文章,它显示了这段有趣的代码:
class Car(object):
def _factory_error_handler(self):
try:
yield
except FactoryColorError, err:
stacktrace = sys.exc_info()[2]
raise ValidationError(err.message), None, stacktrace
def _create_customizer_error_handler(self, vin):
try:
yield
except CustomizerError, err:
self._factory.remove_car(vin)
stacktrace = sys.exc_info()[2]
raise ValidationError(err.message), None, stacktrace
def _update_customizer_error_handler(self, vin):
try:
yield
except CustomizerError, err:
stacktrace = sys.exc_info()[2]
raise ValidationError(err.message), None, stacktrace
def create(self, color, stereo):
with self._factory_error_handler():
vin = self._factory.make_car(color)
with self._create_customizer_error_handler(vin):
self._customizer.update_car(vin, stereo)
return vin
def update(self, vin, color, stereo):
with self._factory_error_handler():
self._factory.update_car_color(vin, color)
with self._update_customizer_error_handler(vin):
self._customizer.update_car(vin, stereo)
return
try
在这里,他们在一个块中没有参数就让步了。with
然后在一个块内使用它。有人可以解释一下这里发生了什么吗?