提问人：Zebby 提问时间：6/27/2022 最后编辑：cardsZebby 更新时间：7/4/2023 访问量：268
如何在 python 中 Rectangle 实例之间的静态方法中使用 comparison 属性
how to use the comparison attribute in a static method between instances of a Rectangle in python
问：
class Rectangle:
"""created a class Rectangles, assigning values"""
number_of_instances = 0
print_symbol = "#"
def __init__(self, width=0, height=0):
self.height = height
self.width = width
Rectangle.number_of_instances += 1
@property
def width(self):
return self.__width
@width.setter
def width(self, value):
if not isinstance(value, int):
raise TypeError("width must be an integer")
elif value < 0:
raise ValueError("width must be >= 0")
self.__width = value
@property
def height(self):
return self.__height
@height.setter
def height(self, value):
if not isinstance(value, int):
raise TypeError("height must be an integer")
elif value < 0:
raise ValueError("height must be >= 0")
self.__height = value
def area(self):
return self.__height * self.__width
def perimeter(self):
if self.__height == 0 or self.__width == 0:
return 0
return (self.__height + self.__width) * 2
def __str__(self):
if self.__width == 0 or self.__height == 0:
return ''
for z in range(self.height - 1):
print(str(self.print_symbol) * self.__width)
return str(self.print_symbol * self.__width)
def __repr__(self):
return "Rectangle({}, {})".format(self.__width, self.__height)
def __del__(self):
print("Bye rectangle...")
Rectangle.number_of_instances -= 1
@staticmethod
def bigger_or_equal(rect_1, rect_2):
if not isinstance(rect_2, Rectangle):
raise TypeError("rect_2 must be an instance of Rectangle")
elif not isinstance(rect_1, Rectangle):
raise TypeError("rect_1 must be an instance of Rectangle")
elif rect_1 == rect_2:
return rect_1
elif rect_1 > rect_2:
return rect_1
elif rect_2 > rect_1:
return rect_2
尝试比较但出现错误...
TypeError: '>' not supported between instances of 'Rectangle' and 'Rectangle'
我应该调用任何函数吗？
答：
-1赞
Taewoo Kim
6/27/2022
#1
假设您在没有任何方法的情况下创建了新类，并比较了该类的两个对象。
class MyClass:
pass
if __name__ == '__main__':
a = MyClass()
b = MyClass()
if a > b:
print("a is bigger than b")
else:
print("a is not bigger than b")
Python 无法比较 和 ，因为两个对象之间没有比较的标准。
因此，当我们考虑时，我们需要告诉口译员。aba is bigger than b
许多语言都提供了一些定义比较的方法，例如 ==、！=、< >。
在 Python 中，您可以使用覆盖 gt 方法定义我们何时说。a is bigger than b
class MyClass:
def __init__(self, val1: int, val2: int):
self.val1 = val1
self.val2 = val2
def __gt__(self, other):
if isinstance(other, MyClass):
return self.val1 * self.val2 > other.val1 * other.val2
else:
raise Exception("cannot compare(>) MyClass and {}".format(type(other)))
if __name__ == '__main__':
a = MyClass(1, 5)
b = MyClass(2, 3)
if a > b:
print("a is bigger than b")
else:
print("a is not bigger than b")
在这里，我定义了.
因此，当我将 > 用于 Myclass 的对象时，解释器会调用 gt 方法。when we consider self is bigger than other
如果想在宽度大于其他矩形时考虑矩形比另一个矩形大，则可以编写如下代码
class Rectangle:
"""created a class Rectangles, assigning values"""
number_of_instances = 0
print_symbol = "#"
def __init__(self, width=0, height=0):
self.height = height
self.width = width
Rectangle.number_of_instances += 1
def __gt__(self, other):
if isinstance(other, Rectangle):
return self.width > other.width
else:
raise Exception("cannot compare(>) Rectangle and {}".format(type(other)))
...
查看 https://docs.python.org/3/library/operator.html#operator
0赞
Ando Abza
7/4/2023
#2
@staticmethod
def bigger_or_equal(rect_1, rect_2):
if not isinstance(rect_1, Rectangle):
raise TypeError("rect_1 must be an instance of Rectangle")
elif not isinstance(rect_2, Rectangle):
raise TypeError("rect_2 must be an instance of Rectangle")
elif rect_1.area() == rect_2.area():
return rect_1
if rect_1.area() >= rect_2.area():
return rect_1
else:
return rect_2
评论
RectangleRectangleRectangle__gt__()__eq__()