如何理解 Python 中的简单断言语句，移动 Point 实例

Question

我为点 class 及其方法编写了以下代码。我想知道如何应用 assert 语句来测试 Point x, y 坐标是否正确移动。我假设 assert 语句在将 move 方法应用于 Point 实例后测试结果坐标的有效性。你能建议我应该如何编写一个断言语句来验证点 class 的所有给定实例是否已正确移动吗？

class Point(object): # Modify here
    #Creates a point on the x,y coordinate system
    def __init__(self,x,y):# The __init__ constructor takes the arguments self( the current instance of the class), and positions x and y
        #Defines x and y variables
        self.x = x # Define self's x attribute.
        self.y = y
    #Moves the given point by dx and dy
    def move(self,dx,dy):#
        #Move the point to different location
        self.x=self.x+dx# the self's x + change in x
        self.y=self.y+dy
    #returns string representation of class Point
    def __str__(self,x,y):
        return "Point location:",(self.x,self.y) 

if __name__ == '__main__':
    # Tests for point
    # ==================================
    def testPoint(x, y):
        p = Point(0, -1)  # create a point instance
        p.move(2, 2)  # Use method move, move the point object by x=2 and y=2

        assert p.x == 2
        assert p.y ==1
        print 'Success! Point tests passed!'


testPoint(0,-1)

Answer 1

这是您需要的吗 -- 为给定输入参数化的方法？

def testPoint(x, y, move_x, move_y):
    p = Point(x, y)  # create a point instance
    p.move(move_x, move_y)  # Use method move, move the point object by x=2 and y=2

    assert p.x == x + move_x and \
           p.y == y + move_y

然后您可以针对各种起点和运动向量执行此操作。

如何理解 Python 中的简单断言语句，移动 Point 实例

How to understand a simple assert statement in Python, moving a Point instance

python

unit-testing

assert