| \u88f8\u5c5e\u6027\u5347\u7ea7<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \u53cd\u8fc7\u6765\u7684\u60c5\u51b5\u4e5f\u4e00\u6837\u6e05\u695a，\u5982\u679c\u4e00\u4e2a\u503c\u5c31\u662f\u5355\u7eaf\u5b58\u7740，\u6ca1\u6709\u4efb\u4f55\u9650\u5236，\u90a3\u76f4\u63a5\u5199 self.name = name \u5c31\u597d，\u5916\u9762 obj.name \u76f4\u63a5\u8bfb\u5199，\u522b\u4e3a\u4e86"\u89c4\u8303"\u628a\u6bcf\u4e2a\u5c5e\u6027\u90fd\u5305\u4e00\u5c42 property\u3002\u6211\u89c1\u8fc7\u6709\u4eba\u7ed9\u5341\u51e0\u4e8c\u5341\u4e2a\u5b57\u6bb5\u5168\u5199\u4e86 getter \u548c setter，\u91cc\u9762\u5c31\u4e00\u53e5 return self._x，\u7eaf\u5c5e\u7ed9\u81ea\u5df1\u627e\u4e8b\u3002<\/p>\n Python \u7684\u597d\u5904\u5728\u4e8e，\u4f60\u4eca\u5929\u5199\u6210\u88f8\u5c5e\u6027，\u54ea\u5929\u771f\u9700\u8981\u6821\u9a8c\u4e86，\u52a0\u4e0a @property \u5c31\u5b8c\u4e8b，\u8c03\u7528\u65b9\u6beb\u53d1\u65e0\u4f24\u3002\u522b\u7684\u8bed\u8a00\u6ca1\u8fd9\u4e2a\u540e\u6094\u836f，\u6240\u4ee5\u624d\u8981\u4e00\u5f00\u59cb\u5c31\u5168\u5199\u6210 get\/set\u3002<\/p>\n 3.8 \u5199 property \u6700\u5bb9\u6613\u72af\u7684\u9519，\u65e0\u9650\u9012\u5f52<\/h4>\n\u8fd9\u4e2a\u5751\u6211\u4ece\u7b2c\u4e00\u6b21\u5199 property \u5c31\u8e29\u4e86，\u800c\u4e14\u62a5\u9519\u4fe1\u606f\u957f\u5230\u8ba9\u4eba\u53d1\u61f5\u3002<\/p>\n >>> class Bad:
\n… @property
\n… def x(self):
\n… return self._x
\n… @x.setter
\n… def x(self, value):
\n… self.x = value
\n…
\n>>> b = Bad()
\n>>> b.x = 1
\nRecursionError: maximum recursion depth exceeded<\/p>\n \u770b setter \u90a3\u4e00\u884c，self.x = value\u3002\u53ef x \u5df2\u7ecf\u662f property \u4e86，\u7ed9 self.x \u8d4b\u503c\u5c31\u7b49\u4e8e\u53c8\u8c03\u4e86\u4e00\u6b21\u8fd9\u4e2a setter，\u7136\u540e\u5b83\u53c8\u7ed9 self.x \u8d4b\u503c，\u65e0\u9650\u5faa\u73af，\u76f4\u5230 Python \u7684\u9012\u5f52\u4e0a\u9650\u628a\u5b83\u6390\u65ad\u3002<\/p>\n b.x = 1
\n \u2502
\n \u2514\u2500\u25ba x.setter(self, 1)
\n \u2502
\n \u2514\u2500\u25ba self.x = 1 \u2190 \u53c8\u662f\u8d4b\u503c，\u53c8\u8c03 setter
\n \u2502
\n \u2514\u2500\u25ba x.setter(self, 1) \u2192 \u2026\u2026\u65e0\u6b62\u5883<\/p>\n \u4fee\u6cd5\u4e00\u53e5\u8bdd，setter \u91cc\u5fc5\u987b\u8d4b\u503c\u7ed9\u53e6\u4e00\u4e2a\u540d\u5b57，\u901a\u5e38\u662f\u52a0\u4e0b\u5212\u7ebf\u7684\u90a3\u4e2a\u3002<\/p>\n >>> class Good:
\n… @property
\n… def x(self):
\n… return self._x
\n… @x.setter
\n… def x(self, value):
\n… self._x = value
\n…
\n>>> g = Good()
\n>>> g.x = 1
\n>>> g.x
\n1
\n>>> g.__dict__
\n{'_x': 1}<\/p>\n \u8bb0\u4f4f\u4e00\u6761\u94c1\u5f8b，@property \u66b4\u9732\u51fa\u6765\u7684\u5c5e\u6027\u540d，\u548c\u5185\u90e8\u771f\u6b63\u5b58\u503c\u7684\u53d8\u91cf\u540d，\u7edd\u5bf9\u4e0d\u80fd\u662f\u540c\u4e00\u4e2a\u3002\u4e00\u65e6\u540c\u540d，getter \u6216 setter \u5c31\u4f1a\u8c03\u7528\u5b83\u81ea\u5df1\u3002<\/p>\n \u518d\u8865\u4e00\u53e5，\u5982\u679c\u4f60\u5728\u8c03\u8bd5\u65f6\u770b\u5230 RecursionError，\u7b2c\u4e00\u4ef6\u4e8b\u5c31\u53bb\u67e5 property \u7684 getter \u548c setter \u91cc\u6709\u6ca1\u6709\u5199\u9519\u53d8\u91cf\u540d\u3002<\/p>\n
\n4. \u7ee7\u627f<\/h3>\n4.1 \u5148\u770b\u6ca1\u6709\u7ee7\u627f\u7684\u65f6\u5019\u6709\u591a\u5570\u55e6<\/h4>\n\u8981\u5199\u4e00\u4e2a\u732b\u7c7b\u548c\u4e00\u4e2a\u72d7\u7c7b，\u5b83\u4eec\u90fd\u6709\u540d\u5b57\u3001\u90fd\u4f1a\u7761\u3001\u90fd\u4f1a\u5403，\u53ea\u6709\u53eb\u58f0\u4e0d\u4e00\u6837\u3002<\/p>\n >>> class Dog:
\n… def __init__(self, name):
\n… self.name = name
\n… def sleep(self):
\n… print(self.name, "\u8db4\u7740\u7761")
\n… def eat(self, food):
\n… print(self.name, "\u5403", food)
\n… def speak(self):
\n… return "\u6c6a\u6c6a"
\n…
\n>>> class Cat:
\n… def __init__(self, name):
\n… self.name = name
\n… def sleep(self):
\n… print(self.name, "\u8db4\u7740\u7761")
\n… def eat(self, food):
\n… print(self.name, "\u5403", food)
\n… def speak(self):
\n… return "\u55b5\u55b5"
\n…<\/p>\n __init__\u3001sleep\u3001eat \u4e09\u4e2a\u65b9\u6cd5\u4e00\u6a21\u4e00\u6837，\u6284\u4e86\u4e24\u904d\u3002\u7b49\u8981\u52a0\u4e2a\u9e1f\u7c7b，\u518d\u6284\u7b2c\u4e09\u904d\u3002\u7b49\u8981\u6539 sleep \u7684\u903b\u8f91，\u4e09\u4e2a\u7c7b\u6328\u4e2a\u6539\u3002<\/p>\n \u7ee7\u627f\u5c31\u662f\u628a\u91cd\u590d\u7684\u90e8\u5206\u5411\u4e0a\u62bd\u3002<\/p>\n Animal \u2190 \u7236\u7c7b，\u653e\u5171\u540c\u7684\u90e8\u5206
\n name \/ sleep \/ eat
\n \u2502
\n \u250c\u2500\u2500\u2500\u2500\u2500\u2500\u253c\u2500\u2500\u2500\u2500\u2500\u2500\u2510
\n \u25bc \u25bc \u25bc
\n Dog Cat Duck \u2190 \u5b50\u7c7b，\u53ea\u5199\u81ea\u5df1\u4e0d\u4e00\u6837\u7684
\n speak speak speak<\/p>\n 4.2 \u7ee7\u627f\u7684\u5199\u6cd5，\u62ec\u53f7\u91cc\u5199\u7236\u7c7b<\/h4>\n>>> class Animal:
\n… def __init__(self, name):
\n… self.name = name
\n… def sleep(self):
\n… print(self.name, "\u8db4\u7740\u7761")
\n… def eat(self, food):
\n… print(self.name, "\u5403", food)
\n…
\n>>> class Dog(Animal):
\n… pass
\n…
\n>>> d = Dog("\u5c0f\u9ed1")
\n>>> d.name
\n'\u5c0f\u9ed1'
\n>>> d.sleep()
\n\u5c0f\u9ed1 \u8db4\u7740\u7761
\n>>> d.eat("\u9aa8\u5934")
\n\u5c0f\u9ed1 \u5403 \u9aa8\u5934<\/p>\n class Dog(Animal) \u8fd9\u4e00\u53e5，Dog \u5c31\u628a Animal \u91cc\u7684\u4e1c\u897f\u5168\u62ff\u4e86\u8fc7\u6765\u3002pass \u8868\u793a\u6682\u65f6\u4ec0\u4e48\u90fd\u4e0d\u52a0，\u4e00\u4e2a\u65b9\u6cd5\u6ca1\u5199，\u5374\u5df2\u7ecf\u80fd\u7528\u7236\u7c7b\u7684\u4e09\u4e2a\u65b9\u6cd5\u3002<\/p>\n \u67e5\u4e00\u4e0b\u7ee7\u627f\u5173\u7cfb\u3002<\/p>\n >>> Dog.__bases__
\n(<class '__main__.Animal'>,)
\n>>> Animal.__bases__
\n(<class 'object'>,)<\/p>\n \u524d\u9762\u90a3\u4e2a __main__ \u662f\u6a21\u5757\u540d，\u5728\u4ea4\u4e92\u7a97\u53e3\u91cc\u6572\u4ee3\u7801\u5c31\u5c5e\u4e8e __main__ \u6a21\u5757，\u5199\u8fdb .py \u6587\u4ef6\u518d\u8dd1，\u663e\u793a\u7684\u4f1a\u662f\u6587\u4ef6\u540d\u3002<\/p>\n \u6700\u540e\u90a3\u884c\u503c\u5f97\u7559\u610f，\u6211\u4eec\u81ea\u5df1\u5199\u7684 Animal \u4e5f\u662f\u6709\u7236\u7c7b\u7684，\u5b83\u7684\u7236\u7c7b\u53eb object\u3002Python \u91cc\u6240\u6709\u7c7b\u6700\u7ec8\u90fd\u7ee7\u627f\u5230 object，\u5b83\u662f\u8001\u7956\u5b97\u3002<\/p>\n 4.3 \u5b50\u7c7b\u52a0\u81ea\u5df1\u7684\u4e1c\u897f<\/h4>\n\u5728\u5b50\u7c7b\u91cc\u5199\u65b0\u65b9\u6cd5，\u5c5e\u4e8e\u5b83\u72ec\u6709\u3002<\/p>\n >>> class Dog(Animal):
\n… def speak(self):
\n… return self.name + " \u6c6a\u6c6a"
\n… def fetch(self):
\n… return self.name + " \u628a\u7403\u53fc\u56de\u6765\u4e86"
\n…
\n>>> d = Dog("\u5c0f\u9ed1")
\n>>> d.speak()
\n'\u5c0f\u9ed1 \u6c6a\u6c6a'
\n>>> d.fetch()
\n'\u5c0f\u9ed1 \u628a\u7403\u53fc\u56de\u6765\u4e86'
\n>>> d.sleep()
\n\u5c0f\u9ed1 \u8db4\u7740\u7761<\/p>\n \u81ea\u5df1\u7684\u65b9\u6cd5\u548c\u7ee7\u627f\u6765\u7684\u65b9\u6cd5\u6df7\u7740\u7528，\u8c03\u7528\u7684\u65f6\u5019\u770b\u4e0d\u51fa\u6765\u54ea\u4e2a\u662f\u54ea\u5c42\u7684，\u8fd9\u6b63\u662f\u7ee7\u627f\u60f3\u8981\u7684\u900f\u660e\u611f\u3002<\/p>\n 4.4 \u65b9\u6cd5\u91cd\u5199，\u5b50\u7c7b\u8bf4\u4e86\u7b97<\/h4>\n\u7236\u7c7b\u7684\u65b9\u6cd5\u4e0d\u5408\u7528，\u5b50\u7c7b\u53ef\u4ee5\u7167\u7740\u540d\u5b57\u91cd\u5199\u4e00\u4e2a\u3002<\/p>\n >>> class Cat(Animal):
\n… def sleep(self):
\n… print(self.name, "\u8737\u5728\u732b\u7a9d\u91cc\u7761")
\n… def speak(self):
\n… return self.name + " \u55b5\u55b5"
\n…
\n>>> c = Cat("\u5c0f\u767d")
\n>>> c.sleep()
\n\u5c0f\u767d \u8737\u5728\u732b\u7a9d\u91cc\u7761
\n>>> d = Dog("\u5c0f\u9ed1")
\n>>> d.sleep()
\n\u5c0f\u9ed1 \u8db4\u7740\u7761<\/p>\n \u540c\u6837\u662f sleep()，\u732b\u548c\u72d7\u7684\u8868\u73b0\u4e0d\u4e00\u6837\u3002\u67e5\u627e\u7684\u987a\u5e8f\u8ddf\u5c5e\u6027\u4e00\u6837，\u5148\u5728\u5b50\u7c7b\u627e，\u627e\u4e0d\u5230\u624d\u53bb\u7236\u7c7b\u3002<\/p>\n c.sleep()
\n \u2502
\n \u251c\u2500 \u67e5 Cat \u91cc\u6709\u6ca1\u6709 sleep \u2192 \u6709，\u7528\u5b83
\n \u2502
\n \u2514\u2500（\u5982\u679c\u6ca1\u6709）\u518d\u67e5 Animal<\/p>\n 4.5 super()，\u628a\u7236\u7c7b\u7684\u65b9\u6cd5\u53eb\u56de\u6765<\/h4>\n\u91cd\u5199\u7684\u65f6\u5019\u7ecf\u5e38\u9047\u5230\u7684\u60c5\u51b5\u662f，\u7236\u7c7b\u90a3\u4e2a\u65b9\u6cd5\u5927\u90e8\u5206\u8fd8\u8981\u7528，\u53ea\u662f\u60f3\u524d\u540e\u52a0\u4e24\u53e5\u3002\u8fd9\u65f6\u5019\u522b\u628a\u4ee3\u7801\u6284\u4e00\u904d，\u7528 super()\u3002<\/p>\n >>> class Dog(Animal):
\n… def sleep(self):
\n… print("\u5148\u8f6c\u4e09\u5708")
\n… super().sleep()
\n… print("\u7761\u7740\u4e86")
\n…
\n>>> d = Dog("\u5c0f\u9ed1")
\n>>> d.sleep()
\n\u5148\u8f6c\u4e09\u5708
\n\u5c0f\u9ed1 \u8db4\u7740\u7761
\n\u7761\u7740\u4e86<\/p>\n super().sleep() \u5c31\u662f"\u8c03\u7528\u7236\u7c7b\u7684 sleep"\u3002\u5b83\u6267\u884c\u5b8c\u4f1a\u7ee7\u7eed\u6267\u884c\u540e\u9762\u7684\u8bed\u53e5，\u6240\u4ee5\u987a\u5e8f\u662f\u524d\u3001\u4e2d\u3001\u540e\u3002<\/p>\n \u5728 __init__ \u91cc\u7528\u5f97\u6700\u591a\u3002\u7236\u7c7b\u5df2\u7ecf\u628a\u901a\u7528\u5b57\u6bb5\u7ed1\u597d\u4e86，\u5b50\u7c7b\u53ea\u9700\u8981\u7ed1\u81ea\u5df1\u591a\u51fa\u6765\u7684\u90a3\u51e0\u4e2a\u3002<\/p>\n >>> class Employee:
\n… def __init__(self, name, salary):
\n… self.name = name
\n… self.salary = salary
\n… def info(self):
\n… return "%s \u6708\u85aa %d" % (self.name, self.salary)
\n…
\n>>> class Manager(Employee):
\n… def __init__(self, name, salary, bonus):
\n… super().__init__(name, salary)
\n… self.bonus = bonus
\n… def info(self):
\n… return super().info() + " \u52a0\u5956\u91d1 %d，\u5171 %d" % (
\n… self.bonus, self.salary + self.bonus)
\n…
\n>>> m = Manager("\u5f20\u4e09", 20000, 5000)
\n>>> print(m.info())
\n\u5f20\u4e09 \u6708\u85aa 20000 \u52a0\u5956\u91d1 5000，\u5171 25000<\/p>\n super().__init__(name, salary) \u4e00\u884c\u9876\u66ff\u4e86\u4e24\u6761\u8d4b\u503c，\u800c\u4e14\u5c06\u6765\u7236\u7c7b\u52a0\u4e86\u65b0\u5b57\u6bb5，\u5b50\u7c7b\u4e0d\u7528\u52a8\u3002<\/p>\n \u8981\u662f\u5fd8\u4e86\u5199 super，\u4f1a\u8fd9\u6837\u3002<\/p>\n >>> class BadManager(Employee):
\n… def __init__(self, name, salary, bonus):
\n… self.bonus = bonus
\n…
\n>>> bm = BadManager("\u674e\u56db", 10000, 2000)
\n>>> bm.bonus
\n2000
\n>>> bm.name
\nAttributeError: 'BadManager' object has no attribute 'name'<\/p>\n \u5b50\u7c7b\u5b9a\u4e49\u4e86 __init__，\u5c31\u628a\u7236\u7c7b\u7684\u5b8c\u5168\u76d6\u4f4f\u4e86，\u7236\u7c7b\u7684\u521d\u59cb\u5316\u4e00\u53e5\u6ca1\u6267\u884c，name \u548c salary \u6839\u672c\u6ca1\u7ed1\u4e0a\u3002\u8fd9\u4e2a\u62a5\u9519\u5728\u65b0\u624b\u5199\u7ee7\u627f\u65f6\u7279\u522b\u5e38\u89c1，\u53ea\u8981\u5b50\u7c7b\u5199\u4e86 __init__，\u7b2c\u4e00\u4ef6\u4e8b\u5c31\u662f super().__init__()\u3002<\/p>\n super() \u8fd8\u6709\u4e2a\u8001\u5199\u6cd5，\u628a\u7236\u7c7b\u540d\u5199\u51fa\u6765\u3002<\/p>\n >>> class OldStyle(Employee):
\n… def __init__(self, name, salary, bonus):
\n… Employee.__init__(self, name, salary)
\n… self.bonus = bonus
\n…
\n>>> o = OldStyle("\u738b\u4e94", 8000, 1000)
\n>>> print(o.info())
\n\u738b\u4e94 \u6708\u85aa 8000<\/p>\n \u80fd\u7528，\u4f46\u7236\u7c7b\u540d\u5199\u6b7b\u5728\u91cc\u9762，\u6539\u4e2a\u7ee7\u627f\u5173\u7cfb\u5c31\u5f97\u8ddf\u7740\u6539\u3002\u65b0\u4ee3\u7801\u4e00\u5f8b\u7528 super()\u3002<\/p>\n 4.6 isinstance \u548c issubclass，\u5224\u65ad\u5173\u7cfb\u7528<\/h4>\n\u60f3\u77e5\u9053\u4e00\u4e2a\u5bf9\u8c61\u662f\u4e0d\u662f\u67d0\u4e2a\u7c7b\u7684，\u7528 isinstance\u3002<\/p>\n >>> isinstance(d, Dog)
\nTrue
\n>>> isinstance(d, Animal)
\nTrue
\n>>> isinstance(d, object)
\nTrue
\n>>> isinstance(d, Cat)
\nFalse<\/p>\n \u72d7\u662f\u72d7，\u72d7\u4e5f\u662f\u52a8\u7269，\u72d7\u5f53\u7136\u662f object\u3002<\/p>\n \u5224\u65ad\u7c7b\u4e4b\u95f4\u7684\u5173\u7cfb\u7528 issubclass\u3002<\/p>\n >>> issubclass(Dog, Animal)
\nTrue
\n>>> issubclass(Animal, Dog)
\nFalse
\n>>> issubclass(Dog, Dog)
\nTrue<\/p>\n \u6709\u4e2a\u5bb9\u6613\u6df7\u7684\u5730\u65b9，isinstance \u4f1a\u628a\u7ee7\u627f\u5173\u7cfb\u7b97\u8fdb\u53bb，\u800c type(x) is SomeClass \u4e0d\u4f1a\u3002<\/p>\n >>> type(d) is Dog
\nTrue
\n>>> type(d) is Animal
\nFalse
\n>>> type(d) is type(d)
\nTrue<\/p>\n \u60f3\u5224\u65ad"\u5b83\u5230\u5e95\u662f\u54ea\u4e2a\u7c7b\u9020\u51fa\u6765\u7684"\u7528 type，\u60f3\u5224\u65ad"\u5b83\u80fd\u4e0d\u80fd\u5f53\u52a8\u7269\u4f7f"\u7528 isinstance\u3002\u65e5\u5e38\u4e1a\u52a1\u4ee3\u7801\u91cc\u540e\u8005\u7528\u5f97\u591a，\u56e0\u4e3a\u5b83\u5bf9\u7ee7\u627f\u53cb\u597d\u3002<\/p>\n 4.7 \u591a\u7ee7\u627f，\u4e00\u4e2a\u7c7b\u80fd\u8ba4\u597d\u51e0\u4e2a\u7239<\/h4>\nPython \u5141\u8bb8\u4e00\u4e2a\u7c7b\u540c\u65f6\u7ee7\u627f\u591a\u4e2a\u7236\u7c7b\u3002<\/p>\n >>> class Flyable:
\n… def fly(self):
\n… return "\u6211\u80fd\u98de"
\n…
\n>>> class Swimmable:
\n… def swim(self):
\n… return "\u6211\u80fd\u6e38"
\n…
\n>>> class Duck(Animal, Flyable, Swimmable):
\n… def speak(self):
\n… return self.name + " \u560e\u560e"
\n…
\n>>> duck = Duck("\u5510\u8001\u9e2d")
\n>>> duck.speak()
\n'\u5510\u8001\u9e2d \u560e\u560e'
\n>>> duck.fly()
\n'\u6211\u80fd\u98de'
\n>>> duck.swim()
\n'\u6211\u80fd\u6e38'
\n>>> duck.sleep()
\n\u5510\u8001\u9e2d \u8db4\u7740\u7761<\/p>\n \u4e09\u4efd\u80fd\u529b\u62fc\u4e00\u8d77\u3002\u8fd9\u79cd\u628a\u4e00\u4e2a\u4e2a\u5c0f\u80fd\u529b\u62fc\u8fdb\u6765\u7684\u5199\u6cd5\u53eb Mixin，\u5b9e\u9645\u9879\u76ee\u91cc\u5f88\u5e38\u89c1\u3002<\/p>\n \u9ebb\u70e6\u51fa\u5728\u591a\u4e2a\u7236\u7c7b\u6709\u540c\u540d\u65b9\u6cd5\u7684\u65f6\u5019，\u5230\u5e95\u542c\u8c01\u7684\u3002Python \u7528\u4e00\u5957\u53eb MRO \u7684\u89c4\u5219\u6765\u6392\u987a\u5e8f\u3002<\/p>\n A
\n \/ \\\\
\n B C
\n \\\\ \/
\n D \u2190 D \u540c\u65f6\u7ee7\u627f B \u548c C，B \u548c C \u53c8\u90fd\u7ee7\u627f A<\/p>\n \u8fd9\u79cd\u7ed3\u6784\u53eb\u83f1\u5f62\u7ee7\u627f，\u662f MRO \u5b58\u5728\u7684\u7406\u7531\u3002\u770b\u4e2a\u4f8b\u5b50\u3002<\/p>\n >>> class A:
\n… def hi(self):
\n… print("A")
\n…
\n>>> class B(A):
\n… def hi(self):
\n… print("B")
\n… super().hi()
\n…
\n>>> class C(A):
\n… def hi(self):
\n… print("C")
\n… super().hi()
\n…
\n>>> class D(B, C):
\n… def hi(self):
\n… print("D")
\n… super().hi()
\n…
\n>>> d = D()
\n>>> d.hi()
\nD
\nB
\nC
\nA<\/p>\n \u6253\u5370\u987a\u5e8f D \u2192 B \u2192 C \u2192 A\u3002\u8fd9\u4e2a\u987a\u5e8f\u4e0d\u662f\u62cd\u8111\u888b\u5b9a\u7684，\u5c31\u662f MRO\u3002<\/p>\n >>> D.__mro__
\n(<class '__main__.D'>, <class '__main__.B'>, <class '__main__.C'>, <class '__main__.A'>, <class 'object'>)<\/p>\n __mro__ \u628a\u8fd9\u4e2a\u7c7b\u7684\u67e5\u627e\u987a\u5e8f\u644a\u7ed9\u4f60\u770b\u3002\u6ce8\u610f A \u53ea\u51fa\u73b0\u4e86\u4e00\u6b21，\u800c\u4e14\u6392\u5728 B \u548c C \u540e\u9762，\u4e0d\u4f1a\u51fa\u73b0 A \u7684 hi \u88ab\u8c03\u7528\u4e24\u904d\u7684\u60c5\u51b5\u3002<\/p>\n \u6bcf\u4e2a\u65b9\u6cd5\u91cc\u90fd\u5199\u4e86 super().hi()，\u8fd9\u5c31\u662f\u534f\u4f5c\u5f0f\u8c03\u7528，\u5b83\u8ba9\u540c\u4e00\u6761\u94fe\u4e0a\u7684\u6bcf\u4e2a\u7c7b\u90fd\u6709\u673a\u4f1a\u6267\u884c\u4e00\u6b21\u3002\u5c11\u5199\u4efb\u4f55\u4e00\u4e2a super()，\u94fe\u6761\u5c31\u65ad\u5728\u90a3\u91cc\u3002<\/p>\n \u591a\u7ee7\u627f\u7528\u5f97\u597d\u662f\u5229\u5668，\u7528\u4e0d\u597d\u662f\u707e\u96be\u3002\u6211\u7ed9\u81ea\u5df1\u5b9a\u7684\u89c4\u77e9\u662f，\u7ee7\u627f\u5c42\u7ea7\u522b\u8d85\u8fc7\u4e24\u5c42，\u80fd\u7528\u7ec4\u5408\u5c31\u522b\u7528\u591a\u7ee7\u627f\u3002\u771f\u8981\u7528，\u7236\u7c7b\u6700\u597d\u90fd\u662f\u90a3\u79cd\u53ea\u6709\u4e00\u4e24\u4e2a\u65b9\u6cd5\u7684\u7eaf\u80fd\u529b\u7c7b\u3002<\/p>\n 4.8 \u591a\u6001，\u540c\u4e00\u4e2a\u52a8\u4f5c\u4e0d\u540c\u7684\u8868\u73b0<\/h4>\n\u6709\u4e86\u7ee7\u627f\u548c\u65b9\u6cd5\u91cd\u5199，\u591a\u6001\u5c31\u81ea\u7136\u5192\u51fa\u6765\u4e86\u3002<\/p>\n >>> class Animal:
\n… def __init__(self, name):
\n… self.name = name
\n… def speak(self):
\n… return "\u2026\u2026"
\n…
\n>>> class Dog(Animal):
\n… def speak(self):
\n… return self.name + " \u6c6a\u6c6a"
\n…
\n>>> class Cat(Animal):
\n… def speak(self):
\n… return self.name + " \u55b5\u55b5"
\n…
\n>>> class Duck(Animal):
\n… def speak(self):
\n… return self.name + " \u560e\u560e"
\n…
\n>>> for a in [Dog("\u5c0f\u9ed1"), Cat("\u5c0f\u767d"), Duck("\u5510\u8001\u9e2d")]:
\n… print(a.speak())
\n\u5c0f\u9ed1 \u6c6a\u6c6a
\n\u5c0f\u767d \u55b5\u55b5
\n\u5510\u8001\u9e2d \u560e\u560e<\/p>\n \u5faa\u73af\u90a3\u4e00\u884c\u5b8c\u5168\u4e0d\u5173\u5fc3\u5217\u8868\u91cc\u5230\u5e95\u662f\u732b\u662f\u72d7，\u5b83\u53ea\u7ba1\u558a speak()，\u6bcf\u4e2a\u5bf9\u8c61\u81ea\u5df1\u77e5\u9053\u8be5\u600e\u4e48\u53eb\u3002\u4e0d\u7528\u5199 if isinstance(a, Dog) \u518d\u5206\u652f，\u52a0\u4e00\u79cd\u65b0\u52a8\u7269，\u8fd9\u6bb5\u5faa\u73af\u4e00\u4e2a\u5b57\u90fd\u4e0d\u7528\u6539\u3002<\/p>\n Python \u5728\u8fd9\u4ef6\u4e8b\u4e0a\u6bd4\u522b\u7684\u8bed\u8a00\u66f4\u677e，\u5b83\u8fd8\u6709\u4e2a\u8bf4\u6cd5\u53eb\u9e2d\u5b50\u7c7b\u578b，\u8d70\u8d77\u6765\u50cf\u9e2d\u5b50\u3001\u53eb\u8d77\u6765\u50cf\u9e2d\u5b50，\u90a3\u5b83\u5c31\u662f\u9e2d\u5b50\u3002\u538b\u6839\u4e0d\u7ee7\u627f\u540c\u4e00\u4e2a\u7236\u7c7b\u4e5f\u884c\u3002<\/p>\n >>> class Robot:
\n… def __init__(self, name):
\n… self.name = name
\n… def speak(self):
\n… return self.name + " \u6ef4，\u6536\u5230"
\n…
\n>>> for a in [Dog("\u5c0f\u9ed1"), Cat("\u5c0f\u767d"), Robot("\u94c1\u86cb")]:
\n… print(a.speak())
\n\u5c0f\u9ed1 \u6c6a\u6c6a
\n\u5c0f\u767d \u55b5\u55b5
\n\u94c1\u86cb \u6ef4，\u6536\u5230<\/p>\n Robot \u8ddf Animal \u4e00\u70b9\u5173\u7cfb\u6ca1\u6709，\u53ea\u8981\u5b83\u6709 speak \u65b9\u6cd5，\u5c31\u80fd\u8fdb\u8fd9\u4e2a\u5faa\u73af\u3002\u8fd9\u79cd"\u6309\u80fd\u529b\u800c\u4e0d\u662f\u6309\u8840\u7edf"\u7684\u9ed8\u5951，\u662f Python \u4ee3\u7801\u5199\u8d77\u6765\u677e\u5feb\u7684\u539f\u56e0\u4e4b\u4e00\u3002<\/p>\n 4.9 \u79c1\u6709\u5c5e\u6027\u548c\u7ee7\u627f，\u4e00\u4e2a\u53cd\u76f4\u89c9\u7684\u7ec6\u8282<\/h4>\n\u524d\u9762\u8bf4\u8fc7 __ \u5f00\u5934\u7684\u5c5e\u6027\u4f1a\u88ab\u6539\u540d\u3002\u5b83\u5728\u7ee7\u627f\u91cc\u7684\u5f71\u54cd\u662f\u8fd9\u6837\u7684\u3002<\/p>\n >>> class Base:
\n… def __init__(self):
\n… self.__value = 1
\n… def get(self):
\n… return self.__value
\n…
\n>>> class Sub(Base):
\n… def get(self):
\n… return self.__value
\n…
\n>>> s = Sub()
\n>>> s.get()
\nAttributeError: 'Sub' object has no attribute '_Sub__value'<\/p>\n Sub \u91cc\u90a3\u4e2a self.__value \u4f1a\u88ab\u6539\u5199\u6210 self._Sub__value，\u800c\u7236\u7c7b\u521b\u5efa\u7684\u662f _Base__value，\u4e24\u4e2a\u540d\u5b57\u5bf9\u4e0d\u4e0a，\u6240\u4ee5\u53d6\u4e0d\u5230\u3002<\/p>\n \u8fd9\u5176\u5b9e\u662f\u6709\u610f\u4e3a\u4e4b，\u53cc\u4e0b\u5212\u7ebf\u7684\u4f5c\u7528\u4e4b\u4e00\u5c31\u662f\u9632\u6b62\u5b50\u7c7b\u4e0d\u5c0f\u5fc3\u8986\u76d6\u7236\u7c7b\u7684\u5185\u90e8\u5c5e\u6027\u3002\u60f3\u8ba9\u5b50\u7c7b\u8bbf\u95ee，\u6539\u6210\u5355\u4e0b\u5212\u7ebf _value \u5c31\u884c，\u90a3\u53ea\u662f\u4e2a\u7ea6\u5b9a，\u4e0d\u505a\u6539\u540d\u3002<\/p>\n >>> class Base:
\n… def __init__(self):
\n… self._value = 1
\n… def get(self):
\n… return self._value
\n…
\n>>> class Sub(Base):
\n… def get(self):
\n… return self._value * 10
\n…
\n>>> s = Sub()
\n>>> s.get()
\n10<\/p>\n 4.10 \u7ee7\u627f\u8fd9\u5757\u6211\u8e29\u8fc7\u7684\u5751<\/h4>\n\u5751\u4e00，\u5b50\u7c7b\u5fd8\u4e86\u8c03 super().__init__()\u3002 4.5 \u6f14\u793a\u8fc7，\u75c7\u72b6\u662f\u7236\u7c7b\u5c5e\u6027\u8bbf\u95ee\u4e0d\u5230\u3002<\/p>\n \u5751\u4e8c，\u7ee7\u627f\u7528\u5728\u4e86\u4e0d\u8be5\u7528\u7684\u5730\u65b9\u3002 \u5224\u65ad\u6807\u51c6\u5c31\u4e00\u53e5\u8bdd，\u770b\u4e24\u8005\u662f"\u662f\u4e00\u79cd"\u8fd8\u662f"\u6709\u4e00\u4e2a"\u3002\u72d7\u662f\u4e00\u79cd\u52a8\u7269，\u7528\u7ee7\u627f；\u6c7d\u8f66\u6709\u4e00\u4e2a\u53d1\u52a8\u673a，\u7528\u7ec4\u5408\u3002<\/p>\n >>> class Engine:
\n… def start(self):
\n… return "\u5f15\u64ce\u542f\u52a8"
\n…
\n>>> class Car:
\n… def __init__(self, brand):
\n… self.brand = brand
\n… self.engine = Engine()
\n… def start(self):
\n… return "%s %s" % (self.brand, self.engine.start())
\n…
\n>>> car = Car("\u6bd4\u4e9a\u8fea")
\n>>> car.start()
\n'\u6bd4\u4e9a\u8fea \u5f15\u64ce\u542f\u52a8'<\/p>\n Car \u6ca1\u6709\u7ee7\u627f Engine，\u800c\u662f\u628a\u53d1\u52a8\u673a\u88c5\u5728\u8eab\u4e0a\u4e86\u3002\u5199\u6210 class Car(Engine) \u4e5f\u80fd\u8dd1，\u4f46\u8bed\u4e49\u5c31\u6210\u4e86"\u6c7d\u8f66\u662f\u4e00\u79cd\u53d1\u52a8\u673a"，\u542c\u7740\u5c31\u4e0d\u5bf9\u3002\u800c\u4e14\u7ec4\u5408\u7684\u597d\u5904\u662f，\u6362\u4e00\u4e2a\u6df7\u52a8\u53d1\u52a8\u673a\u4e0d\u7528\u52a8 Car \u7684\u4ee3\u7801\u3002<\/p>\n \u5751\u4e09，\u7ee7\u627f\u94fe\u592a\u6df1\u3002 \u6211\u63a5\u624b\u8fc7\u4e00\u4e2a\u9879\u76ee，A \u2192 B \u2192 C \u2192 D \u2192 E \u4e94\u5c42，\u60f3\u641e\u6e05\u695a\u67d0\u4e2a\u65b9\u6cd5\u6700\u7ec8\u5728\u54ea\u5b9e\u73b0\u7684，\u5f97\u987a\u7740 __mro__ \u4e00\u8def\u70b9\u8fdb\u53bb，\u6539\u4e00\u884c\u8981\u62c5\u5fc3\u56db\u4e2a\u7236\u7c7b\u3002\u8d85\u8fc7\u4e24\u5c42\u5c31\u8be5\u505c\u4e0b\u6765\u60f3\u60f3\u662f\u4e0d\u662f\u8be5\u62c6\u6210\u7ec4\u5408\u3002<\/p>\n \u5751\u56db，\u591a\u7ee7\u627f\u65f6\u5fd8\u4e86\u5199 super()\u3002 \u94fe\u6761\u65ad\u5728\u4e2d\u95f4，\u540e\u9762\u7684\u7c7b\u4e0d\u4f1a\u88ab\u6267\u884c，\u800c\u4e14\u4e0d\u62a5\u9519，\u53ea\u662f\u5c11\u5e72\u4e86\u6d3b\u3002\u8fd9\u79cd bug \u7279\u522b\u96be\u67e5\u3002<\/p>\n
\n5. \u5b9e\u6218<\/h3>\n\u56db\u4e2a\u4f8b\u5b50，\u4ece\u5c01\u88c5\u5230\u7ee7\u627f，\u628a\u524d\u9762\u51e0\u8282\u4e32\u8d77\u6765，\u5efa\u8bae\u81ea\u5df1\u6572\u4e00\u904d\u3002<\/p>\n 5.1 \u5b9e\u6218\u4e00，\u94f6\u884c\u8d26\u6237\u7cfb\u7edf<\/h4>\n\u9700\u6c42\u3002\u8d26\u6237\u8981\u6709\u6237\u4e3b\u548c\u4f59\u989d，\u53ea\u80fd\u5b58\u3001\u53d6\u3001\u8f6c\u8d26，\u6bcf\u6b21\u64cd\u4f5c\u7559\u6d41\u6c34，\u4f59\u989d\u4e0d\u80fd\u4ece\u5916\u9762\u76f4\u63a5\u6539\u3002<\/p>\n \u601d\u8def\u3002<\/p>\n BankAccount
\n\u251c\u2500\u2500 \u7c7b\u5c5e\u6027 bank_name\u3001total \u2190 \u5168\u884c\u5171\u7528
\n\u251c\u2500\u2500 \u5b9e\u4f8b\u5c5e\u6027 __balance\u3001__logs \u2190 \u53cc\u4e0b\u5212\u7ebf，\u5916\u9762\u78b0\u4e0d\u5230
\n\u251c\u2500\u2500 property balance（\u53ea\u8bfb）\u3001logs（\u8fd4\u56de\u5143\u7ec4）
\n\u2514\u2500\u2500 \u65b9\u6cd5 deposit\u3001withdraw\u3001transfer<\/p>\n \u4ee3\u7801\u3002<\/p>\n class BankAccount:
\n """\u94f6\u884c\u8d26\u6237，\u4f59\u989d\u53ea\u80fd\u901a\u8fc7\u5b58\u53d6\u6b3e\u65b9\u6cd5\u6539\u52a8"""<\/p>\n bank_name = "\u6d3e\u68ee\u94f6\u884c"
\n total = 0<\/p>\n def __init__(self, owner, opening=0):
\n self.owner = owner
\n self.__balance = 0
\n self.__logs = []
\n BankAccount.total += 1
\n if opening > 0:
\n self.deposit(opening)<\/p>\n @property
\n def balance(self):
\n """\u4f59\u989d，\u53ea\u8bfb"""
\n return self.__balance<\/p>\n @property
\n def logs(self):
\n """\u6d41\u6c34，\u8fd4\u56de\u5143\u7ec4\u9632\u6b62\u5916\u9762\u6539"""
\n return tuple(self.__logs)<\/p>\n def deposit(self, amount):
\n """\u5b58\u94b1"""
\n if amount <= 0:
\n raise ValueError("\u5b58\u5165\u91d1\u989d\u5fc5\u987b\u5927\u4e8e 0，\u6536\u5230 %s" % amount)
\n self.__balance += amount
\n self.__logs.append("\u5b58\u5165 %.2f，\u4f59\u989d %.2f" % (amount, self.__balance))
\n return self.__balance<\/p>\n def withdraw(self, amount):
\n """\u53d6\u94b1"""
\n if amount <= 0:
\n raise ValueError("\u53d6\u6b3e\u91d1\u989d\u5fc5\u987b\u5927\u4e8e 0，\u6536\u5230 %s" % amount)
\n if amount > self.__balance:
\n raise ValueError("\u4f59\u989d\u4e0d\u8db3，\u5f53\u524d %.2f \u60f3\u53d6 %.2f" % (self.__balance, amount))
\n self.__balance -= amount
\n self.__logs.append("\u53d6\u51fa %.2f，\u4f59\u989d %.2f" % (amount, self.__balance))
\n return self.__balance<\/p>\n def transfer(self, other, amount):
\n """\u8f6c\u8d26\u7ed9\u53e6\u4e00\u4e2a\u8d26\u6237"""
\n self.withdraw(amount)
\n other.deposit(amount)
\n self.__logs.append("\u8f6c\u7ed9 %s %.2f" % (other.owner, amount))
\n other.__logs.append("\u6536\u5230 %s \u8f6c\u6765 %.2f" % (self.owner, amount))
\n return self.__balance<\/p>\n def __str__(self):
\n return "%s \u7684\u8d26\u6237，\u4f59\u989d %.2f" % (self.owner, self.__balance)<\/p>\n zhang = BankAccount("\u5f20\u4e09", 1000)
\nli = BankAccount("\u674e\u56db", 500)<\/p>\n print("\u5f00\u6237\u884c", BankAccount.bank_name, "\u5df2\u5f00\u8d26\u6237\u6570", BankAccount.total)
\nprint(zhang)
\nprint(li)<\/p>\n zhang.withdraw(200)
\nzhang.transfer(li, 300)<\/p>\n print("\\\\n— \u4ea4\u6613\u4e4b\u540e\u7684\u4f59\u989d")
\nprint(zhang)
\nprint(li)<\/p>\n print("\\\\n— \u5f20\u4e09\u7684\u6d41\u6c34")
\nfor line in zhang.logs:
\n print(" ", line)<\/p>\n print("\\\\n— \u674e\u56db\u7684\u6d41\u6c34")
\nfor line in li.logs:
\n print(" ", line)<\/p>\n print("\\\\n\u4f59\u989d\u662f\u53ea\u8bfb\u7684，\u76f4\u63a5\u6539\u4f1a\u62a5\u9519")
\ntry:
\n zhang.balance = 999999
\nexcept AttributeError as e:
\n print(" AttributeError:", e)<\/p>\n try:
\n zhang.withdraw(99999)
\nexcept ValueError as e:
\n print(" ", type(e).__name__ + ":", e)<\/p>\n print("\\\\n\u6d41\u6c34\u8fd4\u56de\u7684\u662f\u5143\u7ec4，\u6539\u4e0d\u52a8")
\nprint(" ", type(zhang.logs).__name__)<\/p>\n \u8f93\u51fa\u3002<\/p>\n \u5f00\u6237\u884c \u6d3e\u68ee\u94f6\u884c \u5df2\u5f00\u8d26\u6237\u6570 2
\n\u5f20\u4e09 \u7684\u8d26\u6237，\u4f59\u989d 1000.00
\n\u674e\u56db \u7684\u8d26\u6237，\u4f59\u989d 500.00<\/p>\n — \u4ea4\u6613\u4e4b\u540e\u7684\u4f59\u989d
\n\u5f20\u4e09 \u7684\u8d26\u6237，\u4f59\u989d 500.00
\n\u674e\u56db \u7684\u8d26\u6237，\u4f59\u989d 800.00<\/p>\n — \u5f20\u4e09\u7684\u6d41\u6c34
\n \u5b58\u5165 1000.00，\u4f59\u989d 1000.00
\n \u53d6\u51fa 200.00，\u4f59\u989d 800.00
\n \u53d6\u51fa 300.00，\u4f59\u989d 500.00
\n \u8f6c\u7ed9 \u674e\u56db 300.00<\/p>\n — \u674e\u56db\u7684\u6d41\u6c34
\n \u5b58\u5165 500.00，\u4f59\u989d 500.00
\n \u5b58\u5165 300.00，\u4f59\u989d 800.00
\n \u6536\u5230 \u5f20\u4e09 \u8f6c\u6765 300.00<\/p>\n \u4f59\u989d\u662f\u53ea\u8bfb\u7684，\u76f4\u63a5\u6539\u4f1a\u62a5\u9519
\n AttributeError: property 'balance' of 'BankAccount' object has no setter
\n ValueError: \u4f59\u989d\u4e0d\u8db3，\u5f53\u524d 500.00 \u60f3\u53d6 99999.00<\/p>\n \u6d41\u6c34\u8fd4\u56de\u7684\u662f\u5143\u7ec4，\u6539\u4e0d\u52a8
\n tuple<\/p>\n \u590d\u76d8\u3002<\/p>\n balance \u662f\u53ea\u8bfb property，\u5916\u9762\u8bfb\u5f97\u5230\u6539\u4e0d\u52a8，\u6539\u4f59\u989d\u53ea\u6709\u5b58\u53d6\u6b3e\u548c\u8f6c\u8d26\u4e09\u6761\u8def，\u6bcf\u6761\u8def\u90fd\u6709\u6821\u9a8c\u3002\u8fd9\u5c31\u662f\u5c01\u88c5\u6700\u5b9e\u5728\u7684\u597d\u5904，\u94b1\u8fd9\u4e2a\u4e1c\u897f\u4e0d\u8be5\u655e\u7740\u3002<\/p>\n logs \u8fd4\u56de\u7684\u662f tuple(self.__logs) \u800c\u4e0d\u662f\u5217\u8868\u672c\u8eab\u3002\u76f4\u63a5\u628a\u5217\u8868\u4ea4\u51fa\u53bb\u7684\u8bdd，\u5916\u9762\u62ff\u5230\u5f15\u7528\u5c31\u80fd\u968f\u4fbf append \u4f2a\u9020\u6d41\u6c34，\u8f6c\u6210\u5143\u7ec4\u5835\u4f4f\u4e86\u8fd9\u6761\u8def\u3002\u8fd9\u4e5f\u662f\u6211\u5904\u7406"\u5185\u90e8\u6709\u53ef\u53d8\u6570\u636e\u4f46\u8981\u66b4\u9732\u51fa\u53bb"\u65f6\u7684\u5e38\u7528\u624b\u6cd5\u3002<\/p>\n transfer \u91cc\u80fd\u5199 other.__logs，\u56e0\u4e3a\u53cc\u4e0b\u5212\u7ebf\u6539\u540d\u662f\u6309\u7c7b\u540d\u8d70\u7684，BankAccount \u5185\u90e8\u8bbf\u95ee\u4efb\u4f55 BankAccount \u5bf9\u8c61\u7684 __logs \u90fd\u5408\u6cd5\u3002\u540c\u7c7b\u4e4b\u95f4\u4e0d\u8bbe\u9632，\u9632\u7684\u662f\u5916\u9762\u7684\u4ee3\u7801\u3002<\/p>\n BankAccount.total += 1 \u5199\u7684\u662f\u7c7b\u540d\u3002\u5199\u5b8c\u8fd9\u4e00\u884c\u518d\u770b 2.6 \u90a3\u6bb5，\u4e3a\u4ec0\u4e48\u4e0d\u80fd\u5199 self.total += 1，\u90a3\u91cc\u7684\u89e3\u91ca\u5728\u8fd9\u513f\u6709\u4e86\u5b9e\u9645\u573a\u666f\u3002<\/p>\n 5.2 \u5b9e\u6218\u4e8c，\u7535\u5546\u8d2d\u7269\u8f66<\/h4>\n\u9700\u6c42\u3002\u5f80\u8d2d\u7269\u8f66\u52a0\u5546\u54c1\u3001\u6539\u6570\u91cf\u3001\u5220\u884c，\u81ea\u52a8\u7b97\u6298\u6263，\u6253\u5c0f\u7968\u3002<\/p>\n \u601d\u8def\u3002\u4e09\u4e2a\u7c7b\u5404\u7ba1\u4e00\u5c42，\u5178\u578b\u7684\u7ec4\u5408\u5173\u7cfb\u3002<\/p>\n Cart \u2500\u2500\u5305\u542b\u2500\u2500\u25ba CartItem \u2500\u2500\u5f15\u7528\u2500\u2500\u25ba Goods
\n \u2502 \u2502 \u2502
\n \u2502 owner \u2502 goods \/ count \u2502 name \/ price \/ unit
\n \u2502 __items \u2502 subtotal(property)
\n \u2502 total \/ discount \/ payable(property)
\n \u2502 receipt()<\/p>\n \u4ee3\u7801\u3002<\/p>\n import unicodedata<\/p>\n def pad(text, width):
\n """\u6309\u5b9e\u9645\u663e\u793a\u5bbd\u5ea6\u8865\u7a7a\u683c，\u4e2d\u6587\u7b97\u4e24\u5217"""
\n shown = 0
\n for ch in str(text):
\n shown += 2 if unicodedata.east_asian_width(ch) in ("W", "F") else 1
\n return str(text) + " " * max(0, width – shown)<\/p>\n DISCOUNT_RULES = [
\n (200, 0.95),
\n (500, 0.90),
\n (1000, 0.85),
\n]<\/p>\n class Goods:
\n """\u5546\u54c1"""<\/p>\n __slots__ = ("name", "price", "unit")<\/p>\n def __init__(self, name, price, unit="\u4ef6"):
\n self.name = name
\n self.price = price
\n self.unit = unit<\/p>\n def __str__(self):
\n return "%s %.2f\u5143\/%s" % (self.name, self.price, self.unit)<\/p>\n __repr__ = __str__<\/p>\n class CartItem:
\n """\u8d2d\u7269\u8f66\u91cc\u7684\u4e00\u884c，\u5546\u54c1\u52a0\u6570\u91cf"""<\/p>\n def __init__(self, goods, count=1):
\n self.goods = goods
\n self.count = count<\/p>\n @property
\n def subtotal(self):
\n """\u5c0f\u8ba1，\u73b0\u7b97\u7684"""
\n return round(self.goods.price * self.count, 2)<\/p>\n def __str__(self):
\n return pad(self.goods.name, 14) + pad("x" + str(self.count), 6) + "%8.2f" % self.subtotal<\/p>\n class Cart:
\n """\u8d2d\u7269\u8f66"""<\/p>\n def __init__(self, owner):
\n self.owner = owner
\n self.__items = []<\/p>\n def add(self, goods, count=1):
\n """\u52a0\u8d2d，\u5df2\u6709\u5c31\u7d2f\u52a0\u6570\u91cf"""
\n for item in self.__items:
\n if item.goods.name == goods.name:
\n item.count += count
\n return
\n self.__items.append(CartItem(goods, count))<\/p>\n def remove(self, name, count=None):
\n """\u51cf\u6570\u91cf，\u4e0d\u4f20 count \u5c31\u6574\u884c\u5220\u6389"""
\n for i, item in enumerate(self.__items):
\n if item.goods.name == name:
\n if count is None or count >= item.count:
\n self.__items.pop(i)
\n else:
\n item.count -= count
\n return True
\n return False<\/p>\n @property
\n def items(self):
\n return tuple(self.__items)<\/p>\n @property
\n def kinds(self):
\n """\u6709\u51e0\u79cd\u5546\u54c1"""
\n return len(self.__items)<\/p>\n @property
\n def quantity(self):
\n """\u4e00\u5171\u591a\u5c11\u4ef6"""
\n return sum(item.count for item in self.__items)<\/p>\n @property
\n def total(self):
\n """\u539f\u4ef7\u5408\u8ba1"""
\n return round(sum(item.subtotal for item in self.__items), 2)<\/p>\n @property
\n def discount(self):
\n """\u6309\u91d1\u989d\u81ea\u52a8\u6253\u6298"""
\n rate = 1.0
\n for limit, value in DISCOUNT_RULES:
\n if self.total >= limit:
\n rate = value
\n return rate<\/p>\n @property
\n def payable(self):
\n """\u5e94\u4ed8"""
\n return round(self.total * self.discount, 2)<\/p>\n def receipt(self):
\n """\u6253\u5c0f\u7968"""
\n print("=" * 46)
\n print("\u4e70\u5bb6 %s" % self.owner)
\n print("=" * 46)
\n print(" " + pad("\u5546\u54c1", 14) + pad("\u6570\u91cf", 6) + pad("\u5c0f\u8ba1", 8))
\n for item in self.__items:
\n print(" " + str(item))
\n print("-" * 46)
\n print("\u5171 %d \u79cd %d \u4ef6，\u539f\u4ef7 %.2f \u5143" % (self.kinds, self.quantity, self.total))
\n print("\u6298\u6263 %.2f，\u5e94\u4ed8 %.2f \u5143，\u7701 %.2f \u5143"
\n % (self.discount, self.payable, self.total – self.payable))
\n print("=" * 46)<\/p>\n catalog = [
\n Goods("\u673a\u68b0\u952e\u76d8", 299, "\u4e2a"),
\n Goods("\u65e0\u7ebf\u9f20\u6807", 89, "\u4e2a"),
\n Goods("\u663e\u793a\u5668", 1299, "\u53f0"),
\n Goods("USB \u7ebf", 19.9, "\u6839"),
\n]<\/p>\n cart = Cart("\u5f20\u4e09")
\ncart.add(catalog[0])
\ncart.add(catalog[1], 2)
\ncart.add(catalog[3], 3)
\ncart.receipt()<\/p>\n print("\\\\n\u518d\u52a0\u4e00\u53f0\u663e\u793a\u5668，\u770b\u770b\u6298\u6263\u53d8\u5316")
\ncart.add(catalog[2])
\ncart.receipt()<\/p>\n print("\\\\n\u5220\u6389 2 \u6839 USB \u7ebf")
\ncart.remove("USB \u7ebf", 2)
\nprint("\u73b0\u5728 %d \u79cd %d \u4ef6，\u5e94\u4ed8 %.2f" % (cart.kinds, cart.quantity, cart.payable))<\/p>\n print("\\\\n\u8d2d\u7269\u8f66\u91cc\u88c5\u7684\u662f\u5bf9\u8c61")
\nprint(" ", cart.items[0].goods, "\u5355\u4ef7", cart.items[0].goods.price)<\/p>\n \u8f93\u51fa\u3002<\/p>\n ==============================================
\n\u4e70\u5bb6 \u5f20\u4e09
\n==============================================
\n \u5546\u54c1 \u6570\u91cf \u5c0f\u8ba1
\n \u673a\u68b0\u952e\u76d8 x1 299.00
\n \u65e0\u7ebf\u9f20\u6807 x2 178.00
\n USB \u7ebf x3 59.70
\n———————————————-
\n\u5171 3 \u79cd 6 \u4ef6，\u539f\u4ef7 536.70 \u5143
\n\u6298\u6263 0.90，\u5e94\u4ed8 483.03 \u5143，\u7701 53.67 \u5143
\n==============================================<\/p>\n \u518d\u52a0\u4e00\u53f0\u663e\u793a\u5668，\u770b\u770b\u6298\u6263\u53d8\u5316
\n==============================================
\n\u4e70\u5bb6 \u5f20\u4e09
\n==============================================
\n \u5546\u54c1 \u6570\u91cf \u5c0f\u8ba1
\n \u673a\u68b0\u952e\u76d8 x1 299.00
\n \u65e0\u7ebf\u9f20\u6807 x2 178.00
\n USB \u7ebf x3 59.70
\n \u663e\u793a\u5668 x1 1299.00
\n———————————————-
\n\u5171 4 \u79cd 7 \u4ef6，\u539f\u4ef7 1835.70 \u5143
\n\u6298\u6263 0.85，\u5e94\u4ed8 1560.35 \u5143，\u7701 275.35 \u5143
\n==============================================<\/p>\n \u5220\u6389 2 \u6839 USB \u7ebf
\n\u73b0\u5728 4 \u79cd 5 \u4ef6，\u5e94\u4ed8 1526.52<\/p>\n \u8d2d\u7269\u8f66\u91cc\u88c5\u7684\u662f\u5bf9\u8c61
\n \u673a\u68b0\u952e\u76d8 299.00\u5143\/\u4e2a \u5355\u4ef7 299<\/p>\n \u590d\u76d8\u3002<\/p>\n Goods \u7528\u4e86 __slots__，\u5546\u54c1\u5b57\u6bb5\u5c31\u4e09\u4e2a，\u4e0d\u5141\u8bb8\u4e71\u52a0\u3002\u5bf9\u8c61\u591a\u7684\u573a\u666f\u7701\u5185\u5b58，\u4e5f\u5835\u4f4f\u4e86\u62fc\u9519\u5c5e\u6027\u540d\u3002<\/p>\n subtotal\u3001total\u3001discount\u3001payable \u5168\u662f property，\u6ca1\u6709\u4e00\u4e2a\u5728\u5185\u5b58\u91cc\u5b58\u503c，\u5168\u662f\u8bfb\u7684\u65f6\u5019\u73b0\u7b97\u3002\u597d\u5904\u662f\u6539\u6570\u91cf\u3001\u6539\u6298\u6263\u4e4b\u540e\u4e0d\u7528\u624b\u52a8\u540c\u6b65，\u8bfb\u5230\u7684\u6c38\u8fdc\u662f\u6700\u65b0\u7ed3\u679c\u3002\u8fd9\u662f property \u6700\u9002\u5408\u7684\u5730\u65b9\u3002<\/p>\n discount \u90a3\u4e2a\u5b9e\u73b0\u6709\u70b9\u610f\u601d，\u5b83\u4ece DISCOUNT_RULES \u91cc\u987a\u5e8f\u67e5，\u6700\u540e\u7684\u89c4\u5219\u8986\u76d6\u524d\u9762\u7684，\u6240\u4ee5\u6ee1\u4e86 1000 \u5c31\u6253 85 \u6298\u3002\u89c4\u5219\u5199\u5728\u7c7b\u5916\u9762，\u6539\u6298\u6263\u4e0d\u7528\u52a8\u7c7b\u3002<\/p>\n pad \u8fd9\u4e2a\u51fd\u6570\u662f\u7b2c\u516d\u7ae0\u5b9e\u6218\u4e00\u90a3\u4f4d\u7684\u8001\u670b\u53cb，\u4e2d\u6587\u5360\u4e24\u5217\u5bbd\u5ea6，%-14s \u6392\u51fa\u6765\u7684\u8868\u662f\u6b6a\u7684\u3002\u547d\u4ee4\u884c\u91cc\u6253\u4e2d\u6587\u62a5\u8868\u8eb2\u4e0d\u5f00\u5b83\u3002<\/p>\n cart.items[0].goods \u8fd9\u884c\u662f\u7ec4\u5408\u7684\u6837\u5b50，\u8d2d\u7269\u8f66\u4e0d\u5b58\u5546\u54c1\u7684\u540d\u5b57\u548c\u4ef7\u683c，\u5b83\u5b58\u7684\u662f\u5546\u54c1\u5bf9\u8c61\u672c\u8eab\u3002\u5c06\u6765\u5546\u54c1\u8981\u52a0\u5e93\u5b58\u3001\u5206\u7c7b\u3001\u56fe\u7247，CartItem \u4e00\u884c\u90fd\u4e0d\u7528\u6539\u3002<\/p>\n 5.3 \u5b9e\u6218\u4e09，\u56fe\u5f62\u9762\u79ef\u8ba1\u7b97\u5668<\/h4>\n\u9700\u6c42\u3002\u652f\u6301\u5706\u3001\u77e9\u5f62\u3001\u4e09\u89d2\u5f62，\u80fd\u7b97\u9762\u79ef\u548c\u5468\u957f，\u80fd\u653e\u8fdb\u540c\u4e00\u4e2a\u5217\u8868\u91cc\u7edf\u4e00\u5904\u7406，\u8fb9\u957f\u53c2\u6570\u8981\u6821\u9a8c\u3002<\/p>\n \u601d\u8def\u3002<\/p>\n Shape（\u57fa\u7c7b，\u53ea\u5b9a\u63a5\u53e3）
\n area() \/ perimeter() \/ describe()
\n \u2502
\n \u250c\u2500\u2500\u2500\u2500\u2500\u2500\u253c\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2510
\n \u25bc \u25bc \u25bc
\n Circle Rectangle Triangle
\n radius w\/h \u4e09\u8fb9<\/p>\n \u4ee3\u7801\u3002<\/p>\n import math
\nimport unicodedata<\/p>\n def pad(text, width):
\n """\u6309\u5b9e\u9645\u663e\u793a\u5bbd\u5ea6\u8865\u7a7a\u683c，\u4e2d\u6587\u7b97\u4e24\u5217"""
\n shown = 0
\n for ch in str(text):
\n shown += 2 if unicodedata.east_asian_width(ch) in ("W", "F") else 1
\n return str(text) + " " * max(0, width – shown)<\/p>\n class Shape:
\n """\u56fe\u5f62\u57fa\u7c7b，\u53ea\u5b9a\u63a5\u53e3，\u4e0d\u5b9e\u73b0"""<\/p>\n def area(self):
\n raise NotImplementedError("\u5b50\u7c7b\u5fc5\u987b\u5b9e\u73b0 area")<\/p>\n def perimeter(self):
\n raise NotImplementedError("\u5b50\u7c7b\u5fc5\u987b\u5b9e\u73b0 perimeter")<\/p>\n def describe(self):
\n return "%s \u9762\u79ef %.2f \u5468\u957f %.2f" % (self.__class__.__name__, self.area(), self.perimeter())<\/p>\n class Circle(Shape):
\n def __init__(self, radius):
\n if radius <= 0:
\n raise ValueError("\u534a\u5f84\u5fc5\u987b\u5927\u4e8e 0")
\n self.radius = radius<\/p>\n def area(self):
\n return math.pi * self.radius ** 2<\/p>\n def perimeter(self):
\n return 2 * math.pi * self.radius<\/p>\n def __str__(self):
\n return "\u5706 r=%g" % self.radius<\/p>\n class Rectangle(Shape):
\n def __init__(self, width, height):
\n if width <= 0 or height <= 0:
\n raise ValueError("\u957f\u5bbd\u5fc5\u987b\u5927\u4e8e 0")
\n self.width = width
\n self.height = height<\/p>\n def area(self):
\n return self.width * self.height<\/p>\n def perimeter(self):
\n return 2 * (self.width + self.height)<\/p>\n @property
\n def is_square(self):
\n return self.width == self.height<\/p>\n def __str__(self):
\n return "\u77e9\u5f62 %gx%g" % (self.width, self.height)<\/p>\n class Triangle(Shape):
\n def __init__(self, a, b, c):
\n sides = sorted([a, b, c])
\n if sides[0] <= 0:
\n raise ValueError("\u8fb9\u957f\u5fc5\u987b\u5927\u4e8e 0")
\n if sides[0] + sides[1] <= sides[2]:
\n raise ValueError("\u4e24\u8fb9\u4e4b\u548c\u5fc5\u987b\u5927\u4e8e\u7b2c\u4e09\u8fb9")
\n self.a, self.b, self.c = a, b, c<\/p>\n def area(self):
\n """\u6d77\u4f26\u516c\u5f0f"""
\n s = self.perimeter() \/ 2
\n return math.sqrt(s * (s – self.a) * (s – self.b) * (s – self.c))<\/p>\n def perimeter(self):
\n return self.a + self.b + self.c<\/p>\n def __str__(self):
\n return "\u4e09\u89d2\u5f62 %g\/%g\/%g" % (self.a, self.b, self.c)<\/p>\n def total_area(shapes):
\n """\u4e0d\u7ba1\u4ec0\u4e48\u56fe\u5f62，\u6709 area \u5c31\u80fd\u7b97"""
\n return round(sum(s.area() for s in shapes), 2)<\/p>\n shapes = [
\n Circle(3),
\n Rectangle(4, 6),
\n Rectangle(5, 5),
\n Triangle(3, 4, 5),
\n]<\/p>\n print("=" * 52)
\nprint(pad("\u56fe\u5f62", 18) + pad("\u9762\u79ef", 10) + pad("\u5468\u957f", 10))
\nprint("=" * 52)
\nfor s in shapes:
\n print(pad(s, 18) + pad("%.2f" % s.area(), 10) + pad("%.2f" % s.perimeter(), 10))
\nprint("=" * 52)
\nprint("\u5408\u8ba1\u9762\u79ef %.2f" % total_area(shapes))<\/p>\n print("\\\\n\u6b63\u65b9\u5f62\u5224\u65ad", [str(s) for s in shapes if isinstance(s, Rectangle) and s.is_square])<\/p>\n print("\\\\n\u6309\u9762\u79ef\u6392\u5e8f")
\nfor s in sorted(shapes, key=lambda x: x.area(), reverse=True):
\n print(" " + pad(s, 16) + "%10.2f" % s.area())<\/p>\n print("\\\\n\u6ca1\u5b9e\u73b0\u63a5\u53e3\u7684\u8bdd")
\ntry:
\n Shape().area()
\nexcept NotImplementedError as e:
\n print(" NotImplementedError:", e)<\/p>\n print("\\\\n\u53c2\u6570\u6821\u9a8c")
\nfor bad in [lambda: Circle(-1), lambda: Rectangle(0, 5), lambda: Triangle(1, 2, 5)]:
\n try:
\n bad()
\n except ValueError as e:
\n print(" ValueError:", e)<\/p>\n \u8f93\u51fa\u3002<\/p>\n ====================================================
\n\u56fe\u5f62 \u9762\u79ef \u5468\u957f
\n====================================================
\n\u5706 r=3 28.27 18.85
\n\u77e9\u5f62 4×6 24.00 20.00
\n\u77e9\u5f62 5×5 25.00 20.00
\n\u4e09\u89d2\u5f62 3\/4\/5 6.00 12.00
\n====================================================
\n\u5408\u8ba1\u9762\u79ef 83.27<\/p>\n \u6b63\u65b9\u5f62\u5224\u65ad ['\u77e9\u5f62 5×5']<\/p>\n \u6309\u9762\u79ef\u6392\u5e8f
\n \u5706 r=3 28.27
\n \u77e9\u5f62 5×5 25.00
\n \u77e9\u5f62 4×6 24.00
\n \u4e09\u89d2\u5f62 3\/4\/5 6.00<\/p>\n \u6ca1\u5b9e\u73b0\u63a5\u53e3\u7684\u8bdd
\n NotImplementedError: \u5b50\u7c7b\u5fc5\u987b\u5b9e\u73b0 area<\/p>\n \u53c2\u6570\u6821\u9a8c
\n ValueError: \u534a\u5f84\u5fc5\u987b\u5927\u4e8e 0
\n ValueError: \u957f\u5bbd\u5fc5\u987b\u5927\u4e8e 0
\n ValueError: \u4e24\u8fb9\u4e4b\u548c\u5fc5\u987b\u5927\u4e8e\u7b2c\u4e09\u8fb9<\/p>\n \u590d\u76d8\u3002<\/p>\n Shape \u662f\u4e2a\u7eaf\u63a5\u53e3\u7c7b，area \u548c perimeter \u91cc\u76f4\u63a5 raise NotImplementedError\u3002\u8fd9\u4e48\u5199\u7684\u610f\u601d\u662f"\u5b50\u7c7b\u5fc5\u987b\u81ea\u5df1\u5b9e\u73b0，\u5fd8\u4e86\u5c31\u5f53\u573a\u62a5\u9519"，\u6bd4\u7559\u4e2a\u7a7a\u51fd\u6570\u8fd4\u56de 0 \u5f3a\u5f97\u591a，\u8fd4\u56de 0 \u7684\u8bdd\u7b97\u51fa\u6765\u7684\u603b\u9762\u79ef\u4f1a\u6084\u6084\u5c11\u4e00\u5757\u3002<\/p>\n total_area \u548c\u6392\u5e8f\u90a3\u4e24\u5904\u662f\u5168\u7bc7\u6700\u503c\u94b1\u7684\u5730\u65b9\u3002\u8fd9\u4e24\u4e2a\u51fd\u6570\u4ece\u5934\u5230\u5c3e\u6ca1\u5199\u8fc7 isinstance，\u5b83\u4eec\u53ea\u5173\u5fc3\u5bf9\u8c61\u6709\u6ca1\u6709 area\u3002\u5c06\u6765\u52a0\u4e2a Ellipse \u7c7b，\u53ea\u8981\u5b9e\u73b0\u4e86 area，\u76f4\u63a5\u585e\u8fdb\u5217\u8868\u5c31\u80fd\u7b97，\u8fd9\u4e24\u884c\u4ee3\u7801\u4e00\u4e2a\u5b57\u90fd\u4e0d\u7528\u6539\u3002\u8fd9\u5c31\u662f\u591a\u6001\u3002<\/p>\n Triangle \u7684 area \u7528\u4e86\u6d77\u4f26\u516c\u5f0f，\u5185\u90e8\u8c03\u4e86 self.perimeter()\u3002\u5b50\u7c7b\u5185\u90e8\u8c03\u7528\u81ea\u5df1\u7684\u65b9\u6cd5\u7167\u6837\u8d70\u591a\u6001，\u5c06\u6765\u6709\u4eba\u7ee7\u627f Triangle \u6539\u4e86\u5468\u957f\u7b97\u6cd5，\u9762\u79ef\u4f1a\u81ea\u52a8\u8ddf\u7740\u53d8\u3002<\/p>\n \u6821\u9a8c\u653e\u5728 __init__ \u91cc\u800c\u4e0d\u662f area \u91cc，\u7406\u7531\u5f88\u5b9e\u5728，\u8fb9\u957f\u4e0d\u5408\u6cd5\u7684\u5bf9\u8c61\u538b\u6839\u4e0d\u8be5\u88ab\u9020\u51fa\u6765，\u65e9\u62a5\u9519\u6bd4\u665a\u62a5\u9519\u597d\u67e5\u3002<\/p>\n 5.4 \u5b9e\u6218\u56db，\u5b66\u751f\u7ba1\u7406\u7cfb\u7edf，\u628a\u51fd\u6570\u7248\u91cd\u5199\u6210\u7c7b<\/h4>\n\u7b2c\u4e00\u7ae0\u5230\u7b2c\u516d\u7ae0\u6211\u4eec\u4e00\u76f4\u5728\u7528\u5217\u8868\u88c5\u5143\u7ec4\u5904\u7406\u5b66\u751f\u6570\u636e\u3002\u8fd9\u4e00\u8282\u628a\u5b83\u6574\u4e2a\u7ffb\u6210\u7c7b\u3002<\/p>\n \u9700\u6c42\u3002\u5b66\u751f\u6709\u59d3\u540d\u3001\u6027\u522b\u3001\u5206\u6570，\u5206\u6570\u8981\u6821\u9a8c\u3001\u7b49\u7ea7\u8981\u81ea\u52a8\u7b97；\u73ed\u7ea7\u80fd\u52a0\u4eba\u5220\u4eba\u67e5\u4eba，\u80fd\u7ed9\u5e73\u5747\u5206\u3001\u53ca\u683c\u7387\u3001\u6392\u540d\u3001\u7b49\u7ea7\u5206\u7ec4\u3002<\/p>\n \u4ee3\u7801\u3002<\/p>\n import unicodedata<\/p>\n def pad(text, width):
\n """\u6309\u5b9e\u9645\u663e\u793a\u5bbd\u5ea6\u8865\u7a7a\u683c，\u4e2d\u6587\u7b97\u4e24\u5217"""
\n shown = 0
\n for ch in str(text):
\n shown += 2 if unicodedata.east_asian_width(ch) in ("W", "F") else 1
\n return str(text) + " " * max(0, width – shown)<\/p>\n class Student:
\n """\u5b66\u751f，\u5206\u6570\u53d7 property \u4fdd\u62a4"""<\/p>\n __slots__ = ("name", "_score", "gender")<\/p>\n def __init__(self, name, score, gender="\u672a\u77e5"):
\n self.name = name
\n self.gender = gender
\n self.score = score<\/p>\n @property
\n def score(self):
\n return self._score<\/p>\n @score.setter
\n def score(self, value):
\n if not isinstance(value, int):
\n raise TypeError("\u5206\u6570\u5fc5\u987b\u662f\u6574\u6570，\u6536\u5230 %r" % value)
\n if not 0 <= value <= 100:
\n raise ValueError("\u5206\u6570\u8981\u5728 0 \u5230 100 \u4e4b\u95f4，\u6536\u5230 %d" % value)
\n self._score = value<\/p>\n @property
\n def grade(self):
\n """\u7b49\u7ea7，\u6309\u5206\u6570\u73b0\u7b97"""
\n if self._score >= 90:
\n return "A"
\n if self._score >= 80:
\n return "B"
\n if self._score >= 60:
\n return "C"
\n return "D"<\/p>\n @property
\n def passed(self):
\n return self._score >= 60<\/p>\n def __str__(self):
\n return "%s（%s）%d \u5206 %s \u7b49" % (self.name, self.gender, self._score, self.grade)<\/p>\n __repr__ = __str__<\/p>\n class ClassRoom:
\n """\u73ed\u7ea7，\u88c5\u4e00\u5806 Student"""<\/p>\n def __init__(self, title):
\n self.title = title
\n self.__students = []<\/p>\n def add(self, student):
\n if not isinstance(student, Student):
\n raise TypeError("\u53ea\u80fd\u52a0 Student \u5bf9\u8c61，\u6536\u5230 %s" % type(student).__name__)
\n self.__students.append(student)<\/p>\n def find(self, name):
\n for stu in self.__students:
\n if stu.name == name:
\n return stu
\n return None<\/p>\n def remove(self, name):
\n stu = self.find(name)
\n if stu is None:
\n return False
\n self.__students.remove(stu)
\n return True<\/p>\n @property
\n def students(self):
\n return tuple(self.__students)<\/p>\n def __len__(self):
\n return len(self.__students)<\/p>\n def __iter__(self):
\n return iter(self.__students)<\/p>\n @property
\n def average(self):
\n if not self.__students:
\n return 0.0
\n return round(sum(s.score for s in self.__students) \/ len(self.__students), 1)<\/p>\n @property
\n def pass_rate(self):
\n if not self.__students:
\n return 0.0
\n n = sum(1 for s in self.__students if s.passed)
\n return round(n \/ len(self.__students) * 100, 1)<\/p>\n def ranking(self):
\n """\u6309\u5206\u6570\u4ece\u9ad8\u5230\u4f4e\u6392"""
\n return sorted(self.__students, key=lambda s: s.score, reverse=True)<\/p>\n def by_grade(self):
\n """\u6309\u7b49\u7ea7\u5206\u7ec4"""
\n groups = {}
\n for stu in self.__students:
\n groups.setdefault(stu.grade, []).append(stu)
\n return groups<\/p>\n def report(self):
\n """\u6253\u5370\u6210\u7ee9\u5355"""
\n print("=" * 54)
\n print("%s \u5171 %d \u4eba \u5e73\u5747\u5206 %.1f \u53ca\u683c\u7387 %.1f%%"
\n % (self.title, len(self), self.average, self.pass_rate))
\n print("=" * 54)
\n print(pad("\u59d3\u540d", 10) + pad("\u6027\u522b", 8) + pad("\u5206\u6570", 8) + "\u7b49\u7ea7")
\n print("-" * 54)
\n for stu in self.ranking():
\n print(pad(stu.name, 10) + pad(stu.gender, 8)
\n + pad(str(stu.score), 8) + stu.grade)
\n print("-" * 54)
\n for grade in sorted(self.by_grade()):
\n members = self.by_grade()[grade]
\n print("%s \u7b49 %d \u4eba %s" % (grade, len(members),
\n "\u3001".join(s.name for s in members)))
\n print("=" * 54)<\/p>\n klass = ClassRoom("\u9ad8\u4e8c\u4e09\u73ed")
\nfor name, score, gender in [
\n ("\u5f20\u4e09", 88, "\u7537"),
\n ("\u674e\u56db", 95, "\u5973"),
\n ("\u738b\u4e94", 72, "\u7537"),
\n ("\u8d75\u516d", 58, "\u5973"),
\n ("\u5b59\u4e03", 90, "\u7537"),
\n ("\u5468\u516b", 66, "\u5973"),
\n]:
\n klass.add(Student(name, score, gender))<\/p>\n klass.report()<\/p>\n print("\\\\n\u76f4\u63a5\u904d\u5386\u5bf9\u8c61，\u56e0\u4e3a\u5b9e\u73b0\u4e86 __iter__")
\nfor stu in klass:
\n print(" ", stu)<\/p>\n print("\\\\n\u627e\u4eba")
\nstu = klass.find("\u738b\u4e94")
\nprint(" ", stu)
\nprint(" \u7ed9\u4ed6\u52a0 5 \u5206")
\nstu.score = 77
\nprint(" ", stu, "\u7b49\u7ea7", stu.grade)<\/p>\n print("\\\\n\u5206\u6570\u6821\u9a8c\u62e6\u5f97\u4f4f\u810f\u6570\u636e")
\nfor bad in [105, -3, "\u4e5d\u5341"]:
\n try:
\n stu.score = bad
\n except (ValueError, TypeError) as e:
\n print(" %s: %s" % (type(e).__name__, e))<\/p>\n print("\\\\n\u8f6c\u5b66\u8d70\u4e00\u4e2a")
\nklass.remove("\u8d75\u516d")
\nprint(" \u73b0\u5728 %d \u4eba，\u5e73\u5747\u5206 %.1f，\u53ca\u683c\u7387 %.1f%%"
\n % (len(klass), klass.average, klass.pass_rate))<\/p>\n print("\\\\n\u52a0\u9519\u7c7b\u578b\u4f1a\u88ab\u62e6\u4e0b")
\ntry:
\n klass.add(("\u94b1\u4e5d", 80))
\nexcept TypeError as e:
\n print(" TypeError:", e)<\/p>\n \u8f93\u51fa\u3002<\/p>\n ======================================================
\n\u9ad8\u4e8c\u4e09\u73ed \u5171 6 \u4eba \u5e73\u5747\u5206 78.2 \u53ca\u683c\u7387 83.3%
\n======================================================
\n\u59d3\u540d \u6027\u522b \u5206\u6570 \u7b49\u7ea7
\n——————————————————
\n\u674e\u56db \u5973 95 A
\n\u5b59\u4e03 \u7537 90 A
\n\u5f20\u4e09 \u7537 88 B
\n\u738b\u4e94 \u7537 72 C
\n\u5468\u516b \u5973 66 C
\n\u8d75\u516d \u5973 58 D
\n——————————————————
\nA \u7b49 2 \u4eba \u674e\u56db\u3001\u5b59\u4e03
\nB \u7b49 1 \u4eba \u5f20\u4e09
\nC \u7b49 2 \u4eba \u738b\u4e94\u3001\u5468\u516b
\nD \u7b49 1 \u4eba \u8d75\u516d
\n======================================================<\/p>\n \u76f4\u63a5\u904d\u5386\u5bf9\u8c61，\u56e0\u4e3a\u5b9e\u73b0\u4e86 __iter__
\n \u5f20\u4e09（\u7537）88 \u5206 B \u7b49
\n \u674e\u56db（\u5973）95 \u5206 A \u7b49
\n \u738b\u4e94（\u7537）72 \u5206 C \u7b49
\n \u8d75\u516d（\u5973）58 \u5206 D \u7b49
\n \u5b59\u4e03（\u7537）90 \u5206 A \u7b49
\n \u5468\u516b（\u5973）66 \u5206 C \u7b49<\/p>\n \u627e\u4eba
\n \u738b\u4e94（\u7537）72 \u5206 C \u7b49
\n \u7ed9\u4ed6\u52a0 5 \u5206
\n \u738b\u4e94（\u7537）77 \u5206 C \u7b49 \u7b49\u7ea7 C<\/p>\n \u5206\u6570\u6821\u9a8c\u62e6\u5f97\u4f4f\u810f\u6570\u636e
\n ValueError: \u5206\u6570\u8981\u5728 0 \u5230 100 \u4e4b\u95f4，\u6536\u5230 105
\n ValueError: \u5206\u6570\u8981\u5728 0 \u5230 100 \u4e4b\u95f4，\u6536\u5230 -3
\n TypeError: \u5206\u6570\u5fc5\u987b\u662f\u6574\u6570，\u6536\u5230 '\u4e5d\u5341'<\/p>\n \u8f6c\u5b66\u8d70\u4e00\u4e2a
\n \u73b0\u5728 5 \u4eba，\u5e73\u5747\u5206 83.2，\u53ca\u683c\u7387 100.0%<\/p>\n \u52a0\u9519\u7c7b\u578b\u4f1a\u88ab\u62e6\u4e0b
\n TypeError: \u53ea\u80fd\u52a0 Student \u5bf9\u8c61，\u6536\u5230 tuple<\/p>\n \u590d\u76d8\u3002<\/p>\n \u5bf9\u6bd4\u4e00\u4e0b\u5f00\u5934\u90a3\u4e2a\u7528\u5143\u7ec4\u7684\u7248\u672c\u3002\u5b57\u6bb5\u4ece row[0] row[1] \u53d8\u6210\u4e86 stu.name stu.score，\u542b\u4e49\u5199\u5728\u4ee3\u7801\u91cc，\u4e0d\u9760\u7ea6\u5b9a\u3002<\/p>\n \u5206\u6570\u6821\u9a8c\u8fd9\u6b21\u662f\u786c\u7684\u3002Student("\u5f20\u4e09", 999) \u5728\u6784\u9020\u65f6\u5c31\u4f1a\u70b8，\u810f\u6570\u636e\u8fdb\u4e0d\u4e86\u7cfb\u7edf\u3002\u800c\u5143\u7ec4\u7248\u672c\u91cc，999 \u5206\u80fd\u4e00\u8def\u8d70\u5230\u6253\u5370\u73af\u8282，\u6700\u540e\u4ee5"\u5e73\u5747\u5206 1200"\u8fd9\u79cd\u8352\u8c2c\u6570\u5b57\u51fa\u73b0\u5728\u62a5\u8868\u4e0a\u3002<\/p>\n grade \u548c passed \u90fd\u662f\u73b0\u7b97\u7684 property，\u6539\u4e86\u5206\u6570\u7b49\u7ea7\u7acb\u523b\u53d8，\u4e0d\u5b58\u5728"\u5206\u6570\u6539\u4e86\u7b49\u7ea7\u6ca1\u540c\u6b65"\u8fd9\u79cd\u4e8b\u3002<\/p>\n __len__ \u548c __iter__ \u8fd9\u4e24\u4e2a\u7279\u6b8a\u65b9\u6cd5\u8ba9 ClassRoom \u7528\u8d77\u6765\u50cf\u4e2a\u771f\u7684\u5bb9\u5668，len(klass)\u3001for stu in klass \u76f4\u63a5\u5c31\u80fd\u5199\u3002\u521a\u5b66\u7684\u65f6\u5019\u89c9\u5f97\u8fd9\u4fe9\u6ca1\u7528，\u5199\u5230\u7b2c\u4e8c\u4e2a\u7ba1\u7406\u7c7b\u5c31\u77e5\u9053\u6709\u591a\u7701\u4e8b\u3002<\/p>\n add \u91cc\u90a3\u53e5\u7c7b\u578b\u68c0\u67e5\u770b\u7740\u591a\u4f59，\u5b9e\u9645\u6551\u8fc7\u6211\u3002\u66fe\u7ecf\u5f80\u73ed\u7ea7\u91cc\u585e\u4e86\u4e2a\u5b57\u5178，\u62a5\u9519\u62a5\u5728\u6392\u5e8f\u90a3\u4e00\u884c，\u9519\u8bef\u4fe1\u606f\u662f '>' not supported between instances of 'dict' and 'Student'，\u4ece\u8fd9\u884c\u5f80\u4e0a\u627e\u4e86\u5341\u5206\u949f\u624d\u5b9a\u4f4d\u5230\u662f\u52a0\u4eba\u7684\u65f6\u5019\u585e\u9519\u4e86\u3002\u73b0\u5728\u76f4\u63a5\u62e6\u5728\u5165\u53e3，\u62a5\u9519\u4fe1\u606f\u6e05\u695a\u660e\u767d\u3002<\/p>\n
\n6. \u5c0f\u7ed3<\/h3>\n6.1 \u77e5\u8bc6\u6e05\u5355<\/h4>\n\u9762\u5411\u5bf9\u8c61\u6982\u8ff0<\/p>\n |