from math
import pi
1. 定义一个矩形类，拥有属性：长、宽 拥有方法：求周长、求面积
class Rectangle:
def __init__(self
, long, wide
):
self
.a
= long
self
.b
= wide
def Perimeter(self
):
return (self
.a
+ self
.b
) * 2
def acreage(self
):
return self
.a
* self
.b
p1
= Rectangle
(20, 30)
print(p1
.Perimeter
())
2. 定义一个二维点类，拥有属性：x坐标、y坐标 拥有方法：求当前点到另外一个点的距离
class Point:
def __init__(self
, x
=0, y
=0):
self
.x
= x
self
.y
= y
def distance(self
, other
):
return ((self
.x
- other
.x
)**2 + (self
.y
- other
.y
)**2)**0.5
3. 定义一个圆类，拥有属性：半径、圆心 拥有方法：求圆的周长和面积、判断当前圆和另一个圆是否外切
class Circle:
pi
= 3.1415926
def __init__(self
, radius
, center
=Point
(0, 0)):
self
.radius
= radius
self
.center
= center
def perimeter(self
):
return 2*Circle
.pi
*self
.radius
def area(self
):
return Circle
.pi
* self
.radius
** 2
def is_exterior_contact(self
, other
):
return self
.center
.distance
(other
.center
) == self
.radius
+other
.radius
c1
= Circle
(10)
c2
= Circle
(20, Point
(40, 0))
print(c1
.is_exterior_contact
(c2
))
4. 定义一个线段类，拥有属性：起点和终点， 拥有方法：获取线段的长度
class Line:
def __init__(self
, start
: Point
, end
: Point
):
self
.start
= start
self
.end
= end
def length(self
):
return self
.start
.distance
(self
.end
)
l1
= Line
(Point
(0, 0), Point
(100, 100))
print(l1
.length
())
5. 定义一个狗类和一个人类：
狗拥有属性：姓名、性别和品种 拥有方法：叫唤
人类拥有属性：姓名、年龄、狗 拥有方法：遛狗
class Dog:
def __init__(self
, name
, gender
='母狗', breed
='土狗'):
self
.name
= name
self
.gender
= gender
self
.breed
= breed
def bark(self
):
print('汪汪汪!')
class Person:
def __init__(self
, name
, age
=18, dog
=None):
self
.name
= name
self
.age
= age
self
.dog
= dog
def walk_the_dog(self
):
if self
.dog
:
print(f
'{self.name}牵着{self.dog.name}散步!')
else:
print(f
'{self.name}没有狗!')
p1
= Person
('小明')
p2
= Person
('小花')
p1
.dog
= Dog
('大黄')
p1
.walk_the_dog
()
p2
.walk_the_dog
()
