Python类计算长度
我是在模仿海龟模型来画画 这就是我到目前为止所做的:Python类计算长度,python,turtle-graphics,Python,Turtle Graphics,我是在模仿海龟模型来画画 这就是我到目前为止所做的: class Turtle: def __init__(self): self.x = drawer.maxX / 2 self.y = drawer.maxY / 2 self.angle = 0 self.pen_active = True self.pause = 0 self.body = drawer.circle(0, 0, 5,
class Turtle:
def __init__(self):
self.x = drawer.maxX / 2
self.y = drawer.maxY / 2
self.angle = 0
self.pen_active = True
self.pause = 0
self.body = drawer.circle(0, 0, 5, drawer.green, 3)
self.head = drawer.circle(0, 0, 3, drawer.green, 3)
self.length = 0
self.update()
def set_pause(self, n):
self.pause = n
def no_pause(self):
self.set_pause(0)
def hide(self):
self.body.hide()
self.head.hide()
def show(self):
self.body.show()
self.head.show()
def update(self):
self.body.setPos(self.x, self.y)
phi = radians(90 - self.angle)
self.head.setPos(self.x + 5 * cos(phi), self.y + 5 * sin(phi))
drawer.wait(self.pause)
def pen_up(self):
self.pen_active = False
def pen_down(self):
self.pen_active = True
def fly(self, x, y, angle):
self.x = x
self.y = y
self.angle = angle
self.update()
def forward(self, a):
phi = radians(90 - self.angle)
nx = self.x + a * cos(phi)
ny = self.y + a * sin(phi)
if self.pen_active:
drawer.line(self.x, self.y, nx, ny)
self.x = nx
self.y = ny
self.update()
def backward(self, a):
self.forward(-a)
def turn(self, phi):
self.angle += phi
self.update()
def left(self):
self.turn(-90)
def right(self):
self.turn(90)
def length(self):
pass
现在我试图写一个方法来计算画的线的长度,但我不知道怎么做。这条线是在笔放下,乌龟向前或向后移动时画的。如果海龟飞行或转身,则不会绘制线。任何想法
感谢您的帮助。如果我理解正确,您希望保留一份记录,记录您的
海龟自创建之日起所做的向前
和向后
移动的长度
这很简单,只需对变量名小心一点。当前,您将length
用作实例变量(用于保存运行长度总和)和方法名称。前者将隐藏后者,因此您可能需要两个不同的名称
如果我们将实例变量重命名为\u length
,则可以使其如下工作:
class Turtle:
def __init__(self):
# unmodified stuff omitted
self._length = 0
# unmodified methods skipped
def forward(self, a):
# all the current stuff
self._length += abs(a) # absolute value to count backing up as movement
def length():
return self._length
您可以决定不需要简单的length
方法,在这种情况下,您可以返回使用self.length
作为实例变量名(并在需要值时访问属性)。这有帮助吗?更具体地说,