Python 的继承类型

---

继承被定义为将基类的属性继承给子类的机制。下面我们来看看Python 中的继承类。

Python 中的继承类型

继承类型取决于所涉及的子类和父类的数量。Python中有四种继承类型：

单一继承：

单一继承使派生类能够从单个父类继承属性，从而实现代码可重用性以及向现有代码添加新功能。

例子：

# Python program to demonstrate
# single inheritance

# Base class
class Parent:
    def func1(self):
        print("This function is in parent class.")

# Derived class


class Child(Parent):
    def func2(self):
        print("This function is in child class.")


# Driver's code
object = Child()
object.func1()
object.func2()

输出：

This function is in parent class.
This function is in child class.

多重继承：

当一个类可以从多个基类派生时，这种类型的继承称为多重继承。在多重继承中，基类的所有功能都被继承到派生类中。

例子：

• Python3

# Python program to demonstrate
# multiple inheritance

# Base class1
class Mother:
    mothername = ""

    def mother(self):
        print(self.mothername)

# Base class2


class Father:
    fathername = ""

    def father(self):
        print(self.fathername)

# Derived class


class Son(Mother, Father):
    def parents(self):
        print("Father :", self.fathername)
        print("Mother :", self.mothername)


# Driver's code
s1 = Son()
s1.fathername = "RAM"
s1.mothername = "SITA"
s1.parents()

输出：

Father : RAM
Mother : SITA

多级继承 ：

在多级继承中，基类和派生类的特征被进一步继承到新的派生类中。这类似于代表孩子和祖父的关系。

例子：

• Python3

# Python program to demonstrate
# multilevel inheritance

# Base class


class Grandfather:

    def __init__(self, grandfathername):
        self.grandfathername = grandfathername

# Intermediate class


class Father(Grandfather):
    def __init__(self, fathername, grandfathername):
        self.fathername = fathername

        # invoking constructor of Grandfather class
        Grandfather.__init__(self, grandfathername)

# Derived class


class Son(Father):
    def __init__(self, sonname, fathername, grandfathername):
        self.sonname = sonname

        # invoking constructor of Father class
        Father.__init__(self, fathername, grandfathername)

    def print_name(self):
        print('Grandfather name :', self.grandfathername)
        print("Father name :", self.fathername)
        print("Son name :", self.sonname)


# Driver code
s1 = Son('Prince', 'Rampal', 'Lal mani')
print(s1.grandfathername)
s1.print_name()

输出：

Lal mani
Grandfather name : Lal mani
Father name : Rampal
Son name : Prince

层次继承：

当从单一基类创建多个派生类时，这种类型的继承称为层次继承。在此程序中，我们有一个父（基）类和两个子（派生）类。

例子：

• Python3

# Python program to demonstrate
# Hierarchical inheritance


# Base class
class Parent:
    def func1(self):
        print("This function is in parent class.")

# Derived class1


class Child1(Parent):
    def func2(self):
        print("This function is in child 1.")

# Derivied class2


class Child2(Parent):
    def func3(self):
        print("This function is in child 2.")


# Driver's code
object1 = Child1()
object2 = Child2()
object1.func1()
object1.func2()
object2.func1()
object2.func3()

输出：

This function is in parent class.
This function is in child 1.
This function is in parent class.
This function is in child 2.

混合继承：

由多种继承组成的继承称为混合继承。

例子：

• Python3

# Python program to demonstrate
# hybrid inheritance


class School:
    def func1(self):
        print("This function is in school.")


class Student1(School):
    def func2(self):
        print("This function is in student 1. ")


class Student2(School):
    def func3(self):
        print("This function is in student 2.")


class Student3(Student1, School):
    def func4(self):
        print("This function is in student 3.")


# Driver's code
object = Student3()
object.func1()
object.func2()

输出：

This function is in school.
This function is in student 1.

---

原文链接：codingdict.net

---