星空背景

from turtle import *
import random
screen = Screen()
screen.setup(1200, 800)
screen.bgcolor('black')
speed(0)
penup()
hideturtle()
for _ in range(100):
    x = random.random()
    print('the x:', x)
    x = x * 1200 - 1200/2
    y = random.random() * 800 - 800/2
    r = random.random()
    g = random.random()
    b = random.random()
    d = random.randint(0, 3)
    goto(x, y)
    color(r, g, b)
    dot(d)
done()

八大行星

课外练习

到处乱窜的小乌龟

#!/usr/local/bin/env python3
# encoding: utf-8
'''
create a window and a turtle
while the turtle is still in the window:
    generate a random number from 0 to 1
    if the number == 0:
        turn left
    else:
        turn right
    move the turtle forward 50
'''
import random
import turtle
def isInScreen(w, t):
    boundleft = - w.window_width() / 2
    boundright = w.window_width() / 2
    boundtop = w.window_height() / 2
    boundbottom = -w.window_height() / 2
    turtleX = t.xcor()
    turtleY = t.ycor()
    inscreen = True
    if turtleX > boundright or turtleX < boundleft:
        inscreen = False
    if turtleY > boundtop or turtleY < boundbottom:
        inscreen = False
    return inscreen
wn = turtle.Screen()
t = turtle.Turtle()
t.shape('turtle')
while isInScreen(wn, t):
    step = random.randrange(0, 2)
    if step == 0:
        t.left(90)
    else:
        t.right(90)
    t.forward(50)
wn.exitonclick()