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# 面向对象 object:表示该类是从哪个类继承下来的 class Student(object): class_name = '类属性,实例和类都能访问' __slots__ = ('name', 'age') # 定义允许绑定的属性名称，只对当前类有效，对子类无效 def __init__(self, name, score): self.__name = name # 加上两个__就变成私有变量了 注意:__变量名__是特殊变量，这样取名不会变成私有变量 self.score = score def print_info(self): print('%s: %s' % (self.__name, self.score)) tang = Student('tang', 100) tang.age = 666 tang.print_info() print(tang.class_name) print(Student.class_name) print(tang.age) print(isinstance(tang, Student)) #True print(isinstance(tang, object)) #True print(type(tang) == Student) #True print(type(tang) == object) #False dir(tang) #获得一个对象的所有属性和方法 hasattr(tang, 'score') #True hasattr(tang, 'print_info') #True setattr(tang, 'score', 66) getattr(tang, 'score') # 给对象动态绑定方法 def set_age(self, age): self.age = age from types import MethodType tang.set_age = MethodType(set_age, tang) # 给类动态绑定方法 Student.set_age = set_age # 类装饰器 class Student(object): @property def score(self): return self.__score @score.setter def score(self, value): if not isinstance(value, int): raise ValueError('score must be an integer!') if value < 0 or value > 100: raise ValueError('score must between 0 ~ 100!') self.__score = value test = Student() test.score = 100 print(test.score) # 多继承 # 通常，主线都是单一继承下来的，需要混入额外的功能，可以使用多继承 # 这种设计通常称之为MixIn(约定俗成) class Bird(Anmial, FlyableMixIn) # 定制类 # __str__、__repr__、__iter__、__next__、__getitem__、__call__等 # 枚举类 from enum import Enum Month = Enum('Month', ('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec')) for name, member in Month.__members__.items(): print(name, '=>', member, ',', member.value) # 枚举类 from enum import Enum, unique @unique class Weekday(Enum): Sun = 7 Mon = 1 Tue = 2 Wed = 3 Thu = 4 Fri = 5 Sat = 6 for name, member in Weekday.__members__.items(): print(name, '=>', member, "星期", member.value) # 元类:metaclass 从type类型派生 通常用不到 不展开 # 异常处理 # https://docs.python.org/3/library/exceptions.html#exception-hierarchy def test(num): try: 10 / num print('ok') except Exception as e: print('not ok') finally: print('over') test(1) test(0) # 断言 -O参数能关闭断言 python -O test.py def foo(s): n = int(s) assert n != 0, 'n is zero!' return 10 / n def main(): foo('0') main() # 日志 debug info warning error import logging logging.basicConfig(level=logging.INFO) s = '0' n = int(s) logging.info('n = %d' % n) print(10 / n) # pdb python3 -m pdb test.py # l 查看代码 # n 单步执行 # p 变量名 查看变量 # q 结束调试 # c 继续运行 s = '0' n = int(s) print(10 / n) # 手动设置断点 import pdb s = '0' n = int(s) pdb.set_trace() # 运行到这里会自动暂停 print(10 / n) |
