地球公轉走向圖:
from turtle import Shape, Turtle, mainloop, Vec2D as Vec
class GravSys(object):
def __init__(self):
self.planets = []
self.t = 0
self.dt = 0.01
def init(self):
for p in self.planets:
p.init()
def start(self):
for i in range(10000):
self.t += self.dt
for p in self.planets:
p.step()
class Star(Turtle):
def __init__(self, m, x, v, gravSys, shape):
Turtle.__init__(self, shape=shape)
self.penup()
self.m = m
self.setpos(x)
self.v = v
gravSys.planets.append(self)
self.gravSys = gravSys
self.resizemode("user")
self.pendown()
def init(self):
dt = self.gravSys.dt
self.a = self.acc()
self.v = self.v + 0.5*dt*self.a
def acc(self):
a = Vec(0,0)
for planet in self.gravSys.planets:
if planet != self:
v = planet.pos()-self.pos()
a += (G*planet.m/abs(v)**3)*v
return a
def step(self):
dt = self.gravSys.dt
self.setpos(self.pos() + dt*self.v)
if self.gravSys.planets.index(self) != 0:
self.setheading(self.towards(self.gravSys.planets[0]))
self.a = self.acc()
self.v = self.v + dt*self.a
def main():
s = Turtle()
s.reset()
s.getscreen().tracer(0,0)
s.ht()
s.pu()
s.fd(6)
s.lt(90)
s.begin_poly()
s.circle(6, 180)
s.end_poly()
m1 = s.get_poly()
s.begin_poly()
s.circle(6,180)
s.end_poly()
m2 = s.get_poly()
planetshape = Shape("compound")
planetshape.addcomponent(m1,"orange")
planetshape.addcomponent(m2,"blue")
s.getscreen().register_shape("planet", planetshape)
s.getscreen().tracer(1,0)
gs = GravSys()
sun = Star(1000000, Vec(0,0), Vec(0,-2.5), gs, "circle")
sun.color("yellow")
sun.shapesize(1.8)
sun.pu()
earth = Star(12500, Vec(210,0), Vec(0,195), gs, "planet")
earth.pencolor("green")
earth.shapesize(0.8)
moon = Star(1, Vec(220,0), Vec(0,295), gs, "planet")
moon.pencolor("blue")
moon.shapesize(0.5)
gs.init()
gs.start()
return "Done!"
if __name__ == '__main__':
main()
mainloop()
太極圖:
from turtle import *
def yin(radius, color1, color2):
width(3)
color("black", color1)
begin_fill()
circle(radius/2., 180)
circle(radius, 180)
left(180)
circle(-radius/2., 180)
end_fill()
left(90)
up()
forward(radius*0.35)
right(90)
down()
color(color1, color2)
begin_fill()
circle(radius*0.15)
end_fill()
left(90)
up()
backward(radius*0.35)
down()
left(90)
def main():
reset()
yin(200, "black", "white")
yin(200, "white", "black")
ht()
return "Done!"
if __name__ == '__main__':
main()
mainloop()
太陽:
from turtle import *
color('red','yellow')
begin_fill()
while True:
forward(300)
left(100)
if abs(pos())<1:
break
end_fill()
done