我必须将20只海龟放在具有20个边的多边形的顶点上,这样它们才能以规则的间距位于一个圆上。
我有Turtle班,我想在那儿放那20只海龟。我知道如何将更多的海龟放在一个文件中,但是如何将它们围成一圈?
# Already working
class Turtle:
def __init__(self, x, y):
self.x = x
self.y = y
self.heading = 0
self.lines = []
def left(self, angle):
self.heading -= angle
def right(self, angle):
self.heading += angle
def forward(self, d):
nx = self.x + d * math.cos(self.heading * math.pi / 180)
ny = self.y + d * math.sin(self.heading * math.pi / 180)
self.lines.append((self.x, self.y, nx, ny))
self.x, self.y = nx, ny
def save(filename, lines):
f = open(filename, "w")
f.write('<svg viewBox="-500 -500 1000 1000">')
s = '<line x1="{}" y1="{}" x2="{}" y2="{}" style="{}" />'
for i in lines:
for x1, y1, x2, y2 in i:
f.write(s.format(x1, y1, x2, y2, "stroke:black;stroke-width:1"))
f.write("</svg>")
f.close()
# Here is just a try to put more turtles with more lines in one file
# But I can't do this with 20 turtles...
def set_turtles():
global all_lines
turtle_names = []
t_red = Turtle(-100, 0)
turtle_names.append(t_red)
t1 = Turtle(0, 100)
turtle_names.append(t1)
t2 = Turtle(0, -100)
turtle_names.append(t2)
for turtle in turtle_names:
for i in range(4):
turtle.forward(10)
turtle.left(90)
all_lines.append(turtle.lines)
save("drawing_one.html", all_lines)
f.close()
答案 0 :(得分:8)
让我们使用Python的turtle类来帮助解决问题,而不是使用自定义的turtle类进行所有操作。我们仍然需要我们自己的自定义乌龟类(不称为Turtle
),该类可以记录其在调用foward()
时生成的行。另外,实现了一种静态方法来将所有自定义乌龟绘制的所有线转储到SVG文件中。但是我们可以继承的所有其他方法!
使用这种方法来记录线,我们不需要三角函数,而是在调用super().forward(...)
之前记录乌龟的位置,然后再记录乌龟的位置。
最后,我们不需要跟踪我们的自定义乌龟,而是使用Screen().turtles()
并过滤掉那些不是我们自定义类实例的动物。
from turtle import Screen, Turtle
RADIUS = 100
class SVG_Turtle(Turtle):
TEMPLATE = '<line x1="{}" y1="{}" x2="{}" y2="{}" style="{}" />'
STYLE = 'stroke:black;stroke-width:1'
HEADER = '<svg viewBox="-500 -500 1000 1000">'
FOOTER = '</svg>'
def __init__(self, position):
super().__init__(visible=False)
self.lines = []
self.penup()
self.goto(position)
def forward(self, distance):
position = self.position()
super().forward(distance)
self.lines.append((position, self.position()))
@staticmethod
def save(filename):
with open(filename, 'w') as file:
file.write(SVG_Turtle.HEADER)
for turtle in screen.turtles():
if not isinstance(turtle, SVG_Turtle):
continue
for ((x1, y1), (x2, y2)) in turtle.lines:
file.write(SVG_Turtle.TEMPLATE.format(x1, y1, x2, y2, SVG_Turtle.STYLE))
file.write(SVG_Turtle.FOOTER)
screen = Screen()
yertle = Turtle(visible=False) # standard Python turtle to lay down our custom ones
yertle.penup()
yertle.sety(-RADIUS)
screen.tracer(False)
for _ in range(20):
turtle = SVG_Turtle(yertle.position())
turtle.setheading(turtle.towards(0, 0)) # Optional visual detail I added
yertle.circle(RADIUS, 360 / 20, 20)
for turtle in screen.turtles():
if isinstance(turtle, SVG_Turtle):
for _ in range(4):
turtle.forward(10)
turtle.left(90)
screen.tracer(True)
SVG_Turtle.save("drawing.html")
即使不允许使用Python的乌龟来解决自己的乌龟问题,也希望可以为您提供一些有关如何进行和组织代码的想法。