标签:blog div int 而不是 name 没有 参数 pre 自己
面向对象关键词:类,对象,实例,方法
面向对象三大特性:封装,继承,多态
class Foo: # 定义类名 def f1(self): # f1方法 print("success") obj = Foo() # 创建对象 obj.f1() # 通过对象执行方法
类和对象的关系:
self参数是一个Python自动会传值的参数,那个对象执行方法,self就是那个
class SQLhelp(): def __init__(self, a1, a2, a3): # 此方法会自动执行,那个对象执行的方法,self就是那个 print("自动执行init") self.host = a1 self.name = a2 self.pwd = a3 def find(self): pass obj1 = SQLhelp(‘c1.salt.com‘, ‘djc‘, ‘100‘) # 参数分别对应a1,a2,a3 print(obj1.host)
>>>
自动执行
c1.salt.com
对象中封装对象
class c1: def __init__(self, name, obj): self.name = name self.obj = obj class c2: def __init__(self, name, age): self.name = name self.age = age def show(self): print("MDZZ") class c3: def __init__(self, a1): self.aaa = a1 c2_obj = c2("djc", 19) # 要写在c1类之前 c1_obj = c1("sb", c2_obj) ret = c1_obj.obj.name print(ret) >>>djc c3_obj = c3(c1_obj) ret2 = c3_obj.aaa.obj.show() print(ret2) >>>MDZZ
简单单继承
# 继承相当于把父类的方法复制到了子类,而不是去父类里拿
class f1: # 父类,基类 def show(self): print("f1") def foo(self): print(self.name) class f2(f1): # 子类,派生类 def __init__(self, name) self.name = name obj = f2("djc") obj.foo() >>>djc
复杂单继承
class f1: def F1(self): self.F2() # 执行f2的F2 def F2(self): print("f1,F2") class f2(f1): def F3(self): self.F1() # 执行f1的F1 def F2(self): print("f2,F2") obj = f2() obj.F3() # 自己的方法优先,作为子类不要忽略继承的父类的方法,如果自己没有,才去父类里面找 >>> f2,F2
简单多继承
class c1: def f2(self): print("c1") class c2: def f2(self): print("c2") class c3(c2,c1): # 左边的优先 def f3(self): pass obj = c3() obj.f2() >>>c2
稍复杂多继承
class c0: def f2(self): print("c0") class c1: def f2(self): print("c1") class c2(c0): def f1(self): print("c2") class c3(c2,c1): def f3(self): pass obj = c3() obj.f2() >>>c0
复杂多继承
class c_2: def f2(self): print("c_2") class c_1(c_2): def f2(self): print("c_1") class c0(c_2): def f1(self): print("c0") class c1(c_1): def f1(self): print("c1") class c2(c0): def f1(self): print("c2") class c3(c2,c1): def f3(self): pass obj = c3() obj.f2() >>>c-1
class h5: def forever(self): self.run() class h4(h5): def __init__(self): pass def run(self): self.process() def process(self): print("h4") class h3(h4): def __init__(self): pass class h2: def process(self): print("h2") class A(h2, h3): pass obj = A() obj.forever() >>>h2
标签:blog div int 而不是 name 没有 参数 pre 自己
原文地址:http://www.cnblogs.com/learnC/p/6059848.html