名称错误：名称“distancepoint”未定义

Question

import math
class point:
    def __init__(self,p1,p2):
        self.p1 = p1
        self.p2 = p2
    def distancepoint(self):
        x1,y1 = self.p1
        x2,y2 = self.p2
        distance = math.sqrt((x1-x2)**2 + (y1-y2)**2)
        return distance
p1 = point(2,4)
p2 = point(1,6)

distance = distancepoint(p1,p2)
print (f'Distance between 2 points: {distance}')

我是Python初学者。我不知道如何解决这个问题。

Answer 1

您似乎对变量感到困惑：在点类定义中，p1和p2是点坐标，distancepoint是类方法，而后来的p1和p2是点，并且您尝试使用distancepoint作为函数（外部一类）;这就是您可能想做的事情：

import math
class point:
    def __init__(self, x, y):
        self.x = x
        self.y = y
    def distancepoint(self, other):
        distance = math.sqrt((self.x - other.x)**2 + (self.y - other.y)**2)
        return distance
p1 = point(2,4)
p2 = point(1,6)

distance = p1.distancepoint(p2)
print (f'Distance between 2 points: {distance}')

# Distance between 2 points: 2.23606797749979

Answer 2

通过查看代码，您似乎正在尝试编写一个程序来获取两点之间的距离，如果我是正确的，请尝试此代码。

您的代码实际上调用了一个类方法，并且您在没有不可调用的对象的情况下调用它。

import math

class Point:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def distance_to(self, other_point):
        return math.sqrt((self.x - other_point.x)**2 + (self.y - other_point.y)**2)

p1 = Point(2, 4)
p2 = Point(1, 6)

distance = p1.distance_to(p2)
print(f'Distance between 2 points: {distance}')