同样是水，固态，气态，液态的变化，是由温度引起。
from abc import ABCMeta, abstractmethod
# 引入ABCMeta和abstractmethod来定义抽象类和抽象方法
"""
version 1.0
class Water:
def __init__(self, state):
self.__temperature = 25
self.__state = state
def set_state(self, state):
self.__state = state
def change_state(self, state):
if self.__state:
print("由 {} 变为 {}".format(self.__state.get_name(), state.get_name()))
else:
print("初始化为{}".format(state.get_name()))
self.__state = state
def get_temperature(self):
return self.__temperature
def set_temperature(self, temperature):
self.__temperature = temperature
if self.__temperature <= 0:
self.change_state(SolidState("固态"))
elif self.__temperature <= 100:
self.change_state(LiquidState("液态"))
else:
self.change_state(GaseousState("气态"))
def rise_temperature(self, step):
self.set_temperature(self.__temperature + step)
def reduce_temperature(self, step):
self.set_temperature(self.__temperature - step)
def behavior(self):
self.__state.behavior(self)
class State:
def __init__(self, name):
self.__name = name
def get_name(self):
return self.__name
@abstractmethod
def behavior(self, water):
pass
class SolidState(State):
def __init__(self, name):
super().__init__(name)
def behavior(self, water):
print("当前体温： {}".format(str(water.get_temperature())))
class LiquidState(State):
def __init__(self, name):
super().__init__(name)
def behavior(self, water):
print("当前体温： {}".format(str(water.get_temperature())))
class GaseousState(State):
def __init__(self, name):
super().__init__(name)
def behavior(self, water):
print("当前体温： {}".format(str(water.get_temperature())))
def test_state():
water = Water(LiquidState("液态"))
water.behavior()
water.set_temperature(-4)
water.behavior()
water.rise_temperature(18)
water.behavior()
water.rise_temperature(110)
water.behavior()
test_state()
"""
# version 2.0
class Context(metaclass=ABCMeta):
def __init__(self):
self.__states = []
self.__cur_state = None
self.__state_info = 0
def add_state(self, state):
if state not in self.__states:
self.__states.append(state)
def change_state(self, state):
if state is None:
return False
if self.__cur_state is None:
print("初始化为： {}".format(state.get_name()))
else:
print("由 {} 变为 {}".format(self.__cur_state.get_name(), state.get_name()))
self.__cur_state = state
self.add_state(state)
return True
def get_state(self):
return self.__cur_state
def _set_state_info(self, state_info):
self.__state_info = state_info
for state in self.__states:
if state.is_match(state_info):
self.change_state(state)
def _get_state_info(self):
return self.__state_info
class State:
def __init__(self, name):
self.__name = name
def get_name(self):
return self.__name
def is_match(self, state_info):
return False
@abstractmethod
def behavior(self, context):
pass
class Water(Context):
def __init__(self):
super().__init__()
self.add_state(SolidState("固态"))
self.add_state(LiquidState("液态"))
self.add_state(GaseousState("气态"))
self.set_temperature(25)
def get_temperature(self):
return self._get_state_info()
def set_temperature(self, temperature):
self._set_state_info(temperature)
def rise_temperature(self, step):
self.set_temperature(self.get_temperature() + step)
def reduce_temperature(self, step):
self.set_temperature(self.get_temperature() - step)
def behavior(self):
state = self.get_state()
if isinstance(state, State):
state.behavior(self)
def singleton(cls, *args, **kwargs):
instance = {}
def __singletone(*args, **kwargs):
if cls not in instance:
instance[cls] = cls(*args, **kwargs)
return instance[cls]
return __singletone
@singleton
class SolidState(State):
def __init__(self, name):
super().__init__(name)
def is_match(self, state_info):
return state_info < 0
def behavior(self, context):
print("， 我性格高冷， 当前体温： {}".format(context._get_state_info()))
@singleton
class LiquidState(State):
def __init__(self, name):
super().__init__(name)
def is_match(self, state_info):
return 0 <= state_info < 100
def behavior(self, context):
print("我性格温和， 当前体温： {}".format(context._get_state_info()))
@singleton
class GaseousState(State):
def __init__(self, name):
super().__init__(name)
def is_match(self, state_info):
return state_info >= 100
def behavior(self, context):
print("我性格热烈，当前体温： {}".format(context._get_state_info()))
def test_state():
water = Water()
water.behavior()
water.set_temperature(-4)
water.behavior()
water.rise_temperature(18)
water.behavior()
water.rise_temperature(110)
water.behavior()
test_state()
C:\Python36\python.exe C:/Users/Sahara/PycharmProjects/test/python_search.py 初始化为： 液态 我性格温和， 当前体温： 由 液态 变为 固态 ， 我性格高冷， 当前体温： - 由 固态 变为 液态 我性格温和， 当前体温： 由 液态 变为 气态 我性格热烈，当前体温： Process finished with exit code
