如何检查一个列表是否等于使用类创建的另一个列表？

Question

from math import pi

class Circle(object):
    'Circle(x,y,r)'

    def __init__(self, x=0, y=0, r=1):
        self._r = r
        self._x = x
        self._y = y

    def __repr__(self):
        return 'Circle({},{},{})'.\
               format(self.getx(), self.gety(),\
                      self.getr())

    #silly, but has a point: str can be different from repr
    def __str__(self):
        return 'hello world'

    def __contains__(self, item):
        'point in circle'

        px, py = item
        return (self.getx() - px)**2 + \
               (self.gety() - py)**2 < self.getr()**2

    def getr(self):
        'radius'

        return self._r

    def getx(self):
        'x'
        self._lst.append(self._x)
        return self._x


    def gety(self):
        'y'
        self._lst.append(self._y)
        return self._y

    def setr(self,r):
        'set r'
        self._r = r

    def setx(self,x):
        'set x'
        self._x = x

    def sety(self,y):
        'set y'
        self._y = y
    def move(self,x,y):
        self._x += x
        self._y += y
    def concentric(self, d):
        d = self._list
    def area(self):
        'area of circle'

        return (self.getr())**2*pi

    def circumference(self):
        'circumference of circle'
        return 2*self.getr()*pi

My question is worded kinda awkwardly but what I am trying to do is check if 2 different circles have the same center (x,y) . I think the easiest way to solve this would be to input the 2 points into a list but I am not sure how to compare the 2 lists as every time i try my code it adds everything to the same list

Answer 1

Add the following method to your Circle class.

def equal_center(self, other):
    'check if another circle has same center'
    return (self._x == other._x) & (self._y == other._y)

Usage

C1 = Circle(3, 5, 8)
C2 = Circle(3, 5, 10)
C3 = Circle(3, 2, 1)

C1.equal_center(C2)  # True
C1.equal_center(C3)  # False

Answer 2

I would recommend creating a function which takes two circle objects and returns if the coordinates are the same or not by comparing the x and y values of each object:

def same_center(circle_1, circle_2):
  if circle_1.getx() == circle_2.getx() and circle_1.gety() == circle_2.gety():
    return True
  else:
    return False

This solution is much easier than using lists and should be easy to implement.

Answer 3

If you have two instances of the class...

a = Circle(0,0,1)
b = Circle(0,0,1)

You could add them to a list of circles...

circles = [a,b]

And loop through the list, checking their values...

for i in circles:
    for j in filter(lambda x  : x != i, circles):
        if i._x == j._x and i._y == j._y:
            return True #two circles have same center

This should work for n instances of the class, though if its only two you want to check

if a._x == b._x and a._y == a._y:
   return True