Python外观模式详细操作教程
# Filename : example.py
# Copyright : 2020 By Bianchenghao6
# Author by : bianchenghao6.com
# Date : 2020-08-22
class _IgnitionSystem(object):
@staticmethod
def produce_spark():
return True
class _Engine(object):
def __init__(self):
self.revs_per_minute = 0
def turnon(self):
self.revs_per_minute = 2000
def turnoff(self):
self.revs_per_minute = 0
class _FuelTank(object):
def __init__(self, level=30):
self._level = level
@property
def level(self):
return self._level
@level.setter
def level(self, level):
self._level = level
class _DashBoardLight(object):
def __init__(self, is_on=False):
self._is_on = is_on
def __str__(self):
return self.__class__.__name__
@property
def is_on(self):
return self._is_on
@is_on.setter
def is_on(self, status):
self._is_on = status
def status_check(self):
if self._is_on:
print("{}: ON".format(str(self)))
else:
print("{}: OFF".format(str(self)))
class _HandBrakeLight(_DashBoardLight):
pass
class _FogLampLight(_DashBoardLight):
pass
class _Dashboard(object):
def __init__(self):
self.lights = {"handbreak": _HandBrakeLight(), "fog": _FogLampLight()}
def show(self):
for light in self.lights.values():
light.status_check()
# Facade
class Car(object):
def __init__(self):
self.ignition_system = _IgnitionSystem()
self.engine = _Engine()
self.fuel_tank = _FuelTank()
self.dashboard = _Dashboard()
@property
def km_per_litre(self):
return 17.0
def consume_fuel(self, km):
litres = min(self.fuel_tank.level, km / self.km_per_litre)
self.fuel_tank.level -= litres
def start(self):
print("\nStarting...")
self.dashboard.show()
if self.ignition_system.produce_spark():
self.engine.turnon()
else:
print("Can't start. Faulty ignition system")
def has_enough_fuel(self, km, km_per_litre):
litres_needed = km / km_per_litre
if self.fuel_tank.level > litres_needed:
return True
else:
return False
def drive(self, km = 100):
print("\n")
if self.engine.revs_per_minute > 0:
while self.has_enough_fuel(km, self.km_per_litre):
self.consume_fuel(km)
print("Drove {}km".format(km))
print("{:.2f}l of fuel still left".format(self.fuel_tank.level))
else:
print("Can't drive. The Engine is turned off!")
def park(self):
print("\nParking...")
self.dashboard.lights["handbreak"].is_on = True
self.dashboard.show()
self.engine.turnoff()
def switch_fog_lights(self, status):
print("\nSwitching {} fog lights...".format(status))
boolean = True if status == "ON" else False
self.dashboard.lights["fog"].is_on = boolean
self.dashboard.show()
def fill_up_tank(self):
print("\nFuel tank filled up!")
self.fuel_tank.level = 100
# the main function is the Client
def main():
car = Car()
car.start()
car.drive()
car.switch_fog_lights("ON")
car.switch_fog_lights("OFF")
car.park()
car.fill_up_tank()
car.drive()
car.start()
car.drive()
if __name__ == "__main__":
main()
# Filename : example.py
# Copyright : 2020 By Bianchenghao6
# Author by : bianchenghao6.com
# Date : 2020-08-22
Starting...
_HandBrakeLight: OFF
_FogLampLight: OFF
Drove 100km
24.12l of fuel still left
Drove 100km
18.24l of fuel still left
Drove 100km
12.35l of fuel still left
Drove 100km
6.47l of fuel still left
Drove 100km
0.59l of fuel still left
Switching ON fog lights...
_HandBrakeLight: OFF
_FogLampLight: ON
Switching OFF fog lights...
_HandBrakeLight: OFF
_FogLampLight: OFF
Parking...
_HandBrakeLight: ON
_FogLampLight: OFF
Fuel tank filled up!
Can't drive. The Engine is turned off!
Starting...
_HandBrakeLight: ON
_FogLampLight: OFF
Drove 100km
94.12l of fuel still left
Drove 100km
88.24l of fuel still left
Drove 100km
82.35l of fuel still left
Drove 100km
76.47l of fuel still left
Drove 100km
70.59l of fuel still left
Drove 100km
64.71l of fuel still left
Drove 100km
58.82l of fuel still left
Drove 100km
52.94l of fuel still left
Drove 100km
47.06l of fuel still left
Drove 100km
41.18l of fuel still left
Drove 100km
35.29l of fuel still left
Drove 100km
29.41l of fuel still left
Drove 100km
23.53l of fuel still left
Drove 100km
17.65l of fuel still left
Drove 100km
11.76l of fuel still left
Drove 100km
5.88l of fuel still left
Drove 100km
0.00l of fuel still left