这种工厂模式用得少，
可能在游戏类的编程中用得比较多吧。
这个思路清晰一定要OK的。
class Frog:
def __init__(self, name):
self.name = name
def __str__(self):
return self.name
def interact_with(self, obstacle):
print('{} the Frog encouners {} and {}!'.format(self,
obstacle,
obstacle.action()))
class Bug:
def __str__(self):
return 'a bug'
def action(self):
return 'eats it'
class FrogWorld:
def __init__(self, name):
print(self)
self.player_name =name
def __str__(self):
return '\n\n\t-------- Frog World ------'
def make_character(self):
return Frog(self.player_name)
def make_obstacle(self):
return Bug()
class Wizard:
def __init__(self, name):
self.name = name
def __str__(self):
return self.name
def interact_with(self, obstacle):
print('{} the Wizard battles against {} and {}!'.format(self,
obstacle,
obstacle.action()))
class Ork:
def __str__(self):
return 'an evil ork'
def action(self):
return 'kills it'
class WizardWorld:
def __init__(self, name):
print(self)
self.player_name = name
def __str__(self):
return '\n\n\t-------- Wizard World ------'
def make_character(self):
return Wizard(self.player_name)
def make_obstacle(self):
return Ork()
class GameEnvironment:
def __init__(self, factory):
self.hero = factory.make_character()
self.obstacle = factory.make_obstacle()
def play(self):
self.hero.interact_with(self.obstacle)
def validate_age(name):
try:
age = input('Welcome {}. How old are you? '.format(name))
age = int(age)
except ValueError as err:
print('Age {} is invalid, please try again...'.format(age))
return (False, age)
return (True, age)
def main():
name = input("Hello. What's your name? ")
valid_input = False
while not valid_input:
valid_input, age = validate_age(name)
game = FrogWorld if age < 18 else WizardWorld
environment = GameEnvironment(game(name))
environment.play()
if __name__ == '__main__':
main()
