Class GravSys

Lib/turtledemo/planet_and_moon.py:21–33

G = 8

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):