Python N-Body Orbital Simulation

Gravity.py

import math
import random
import matplotlib.pyplot as plot
from mpl_toolkits.mplot3d import Axes3D

class point:
    def __init__(self, x,y,z):
        self.x = x
        self.y = y
        self.z = z

class body:
    def __init__(self, location, mass, velocity, name = ""):
        self.location = location
        self.mass = mass
        self.velocity = velocity
        self.name = name