# super()# MRO + super ⾯面试题
# super是查找mro顺序中的下一个
# 单继承中我们可以认为super是对父类中的属性或方法的引入
class ShengWu:
def dong(self): # 实例方法
print(self)
print("我是生物")
class Animal(ShengWu):
pass
class Cat(Animal):
def dong(self): # 子类中出现了和父类重名的内容. 表示对父类的方法的覆盖(重写). 半盖(java)
super(Animal, self).dong() # 定位到Animal. 找Animal的下一个
# super(类, 对象).方法() 找到MRO中的类. 找这个类的下一个. 去执行方法
print("我的猫也会动")
# 找MRO中的下一个
# Cat -> Animal -> ShengWu
c = Cat()
print(c)
c.dong()
# MRO + super ⾯试题
class Init(object):
def __init__(self, v):
print("init")
self.val = v # 2
class Add2(Init):
def __init__(self, val): # 2
print("Add2")
super(Add2, self).__init__(val)
print(self.val) # 5.0
self.val += 2 # 7.0
class Mult(Init):
def __init__(self, val):
print("Mult")
super(Mult, self).__init__(val)
self.val *= 5 # 5.0
class HaHa(Init):
def __init__(self, val):
print("哈哈")
super(HaHa, self).__init__(val)
self.val /= 5 # 1.0
class Pro(Add2, Mult, HaHa): #
pass
class Incr(Pro):
def __init__(self, val): # 5
super(Incr, self).__init__(val)
self.val += 1 # 8.0
'''
add2
Mult
哈哈
init
5.0
8.0
Add2
init
2
4
'''
# Incr, pro, add2, mult, haha, Init
p = Incr(5)
print(p.val) # ?
# Add2 init
c = Add2(2)
print(c.val) # ?
# ------------------------------------------------------------------------------------------------------------#
# 新式类的MRO(重点, 难点) C3算法
# 先拆分
# 再合并 第一项的头和后面所有项的尾进行比较如果出现了. 就拿出来 如果没出现. 下一项....
class A:
pass
class B(A):
pass
class C(A):
pass
class D(B, C):
pass
class E(C, A):
pass
class F(D, E):
pass
class M(F, E):
pass
class N:
pass
class P(M,N):
pass
class G(P):
pass
class O:
pass
class X(O):
pass
class H(G, X, F):
pass
print(H.__mro__)
'''
L(H) = H + L(G) + L(X) + L(F) + GXF HGPMXFDBECANO
L(G) = G + L(P) + P # GPMFDBECAN
L(X) = X + L(O) + O # XO
L(F) = F + L(D) + L(E) + DE # FDBECA
L(P) = P + L(M) + L(N) + MN # PMFDBECAN
L(D) = D + L(B) + L(C) + BC # DBCA
L(E) = E + L(C) + L(A) + CA # ECA
L(M) = M + L(F) + L(E) + FE # ECA ECA E MFDBECA
'''
'''
L(H) = H + L(G) + X+ L(F) HGPMFDBECAN FDBECA
L(G) = G + L(P) GPMFDBECAN
L(F) = F + L(D) + L(E) FDBECA
L(P) = P + L(M) + L(N) PMFDBECAN
L(D) = D + L(B) + L(C) DBCA
L(E) = E + L(C) + L(A) ECA
L(M) = M + L(F) + L(E) MFDBECA
L(N) = N
L(B) = B + L(A) BA
L(C) = C + L(A) CA
L(A) = A
'''
'''
设L为查找方法的MRO顺序
L(H) = H + L(G) + L(F)
L(G) = G + L(E)
L(F) = F + L(D) + L(E)
L(D) = D + L(B) + L(C)
L(B) = B + L(A)
L(E) = E + L(C) + L(A)
L(C) = C + L(A)
L(A) = A
合并. 从下向上合并. 拿出每一项的头和后一项的身体进行比较. 如果出现了. 就过, 从后一项的头继续去比较. 如果不出现就出来
HGFDBECA
L(H) = H + L(G) + L(F) ECA + FDBECA
L(G) = G + L(E) GECA
L(F) = F + L(D) + L(E) FDBECA
L(D) = D + L(B) + L(C) DBCA
L(B) = B + L(A) BA
L(E) = E + L(C) + L(A) ECA
L(C) = C + A CA
L(A) = A
新式类通过__mro__可以直接看到MRO的结果
'''
# HGF DBE CA object
# print(H.__mro__)
# 给面试官用的
