class OneDigitNumericValue:
	def __init__(self, default_val=5):
		self.value = default_val

	def __add__(self, other_value):
		if not isinstance(other_value, int):
			raise AttributeError("The value is not an integer.")
		new_value = self.value + other_value

		if not (0 < new_value < 9):
			raise AttributeError("The value is not between 0 and 9.")

		return new_value

	def __repr__(self):
		return str(self.value)


class Person:
	moods = {
		"happy": OneDigitNumericValue(),
		"angry": OneDigitNumericValue(),
		"sad": OneDigitNumericValue()
	}

	def update_states(self, state_updates: {}):
		for mood, val_change in state_updates.items():
			print('before assignment:', self.moods[mood])
			self.moods[mood] + val_change
			print('before assignment:', self.moods[mood])
			self.moods[mood] += val_change
			print("after assignment:", self.moods[mood])


p = Person()

for mood, val in p.moods.items():
	print(mood, val)

p.update_states({
	"happy": 2,
	"sad": -2
})

for mood, val in p.moods.items():
	print(mood, val)