绘制同心正方形

Question

在阅读本书 "How to think like..." 时，我被练习 4.9.2 卡住了。

问题是："Write a program to draw this. Assume the innermost square is 20 units per side, and each successive square is 20 units bigger, per side, than the one inside it"

以下代码代表了我到目前为止的进展：

import turtle
wn = turtle.Screen()
wn.bgcolor("lightgreen")
tess = turtle.Turtle()

def draw_square(t,size):
    for i in range(4):
        tess.forward(size)
        tess.left(90)

size = 20
for j in range(3):
   tess.pensize(3)
   draw_square(tess,size)
   size = size + 20
   tess.penup()
   tess.goto(-20, -20)
   tess.pendown()

wn.mainloop()

有好心人指点方向吗？

谢谢！

斯文

Answer 1

问题出在这里：

tess.goto(-20, -20)

你有两个问题。首先，如果每个正方形大 20 个单位并且您将每个正方形偏移 (-20, -20)，则所有正方形将共享一个角。相反，您想将正方形的角偏移 (-10, -10)，以便内部正方形在所有边上偏移 10 个单位。

第二个问题是.goto(x, y)设置的是绝对位置，而不是偏移量。要移动到偏移量，您需要根据偏移量计算新的绝对位置：

tess.goto(tess.xcor()-10, tess.ycor()-10)

或

tess.goto(tess.pos() + (-10, -10))

Answer 2

有时当您遇到困难时，使用海龟图形的一个好方法是跳出正方形思考。如果我们将期望的结果视为画得不好的同心圆，那么问题就简化为：

from turtle import Turtle, Screen

HYPOTENUSE = (2 ** 0.5) / 2

screen = Screen()
screen.bgcolor("lightgreen")

tess = Turtle()
tess.pencolor("red")
tess.setheading(45)
tess.width(3)

for radius in range(20, 20 * 5 + 1, 20):
    tess.penup()
    tess.goto(radius/2, -radius/2)
    tess.pendown()
    tess.circle(radius * HYPOTENUSE, steps=4)

screen.exitonclick()

输出

Answer 3

import turtle
def drawSquare (t, size):
    for i in range (4):
        t.forward(size)
        t.left(90)

def main():
    wn = turtle.Screen()
    wn.bgcolor('black')
    pat = turtle.Turtle()
    pat.pensize(2)
    pat.speed(10)
    pat.color('blue')
    space = -10

    for i in range(20, 105, 20):
        drawSquare(pat,i)
        pat.up()
        pat.goto(space, space)
        pat.down()
        space = space - 10
    wn.exitonclick()
main()

Answer 4

import turtle
def draw_sqr(name,size):
    for i in range(4):
        name.forward(size)
        name.left(90)
    name.penup()
    name.backward(10)
    name.right(90)
    name.forward(10)
    name.left(90)
    name.pendown()

window = turtle.Screen()
window.bgcolor('lightgreen')
window.title("conc_sqr")

x = turtle.Turtle()
x.color('hotpink')
x.pensize(3)

for i in range(5):
    draw_sqr(x,20 + 20*i)

window.mainloop()

Answer 5

def draw_rectangle(animal, width, height): 

    for _ in range(2):
        animal.forward(width)
        animal.left(90)
        animal.forward(height)
        animal.left(90)

def draw_square(animal, size): 
    draw_rectangle(animal, size, size)

def make_window(back_color,title):

    window = turtle.Screen()
    window.bgcolor(back_color)
    window.title(title)
    return window

def make_turtle(color, size):

    animal = turtle.Turtle()
    animal.color(color)
    animal.pensize(size)
    return animal

import turtle
window = make_window("lightgreen","Squares")
tess = make_turtle("hotpink",3)

size_sqr=20
adjustment = 10
for _ in range(5):
    draw_square(tess,size_sqr)
    size_sqr += 20
    tess.penup()
    tess.backward(20/2)
    tess.right(90)
    tess.forward(20/2)
    tess.left(90)
    tess.pendown()

Answer 6

    import turtle 

    def drawsquare(t,sz): #(turtle, size)
        for i in range(4):
            t.fd(sz)
            t.right(90)
        
    def main():
        wn = turtle.Screen()
        your_turtle = turtle.Turtle()
        your_turtle.pensize(3)
        wn.bgcolor("light green")
        your_turtle.pencolor("hot pink")
        
        for i in range(1,6):
            drawsquare(your_turtle,20*i)
            your_turtle.up()
            your_turtle.left(135)
            your_turtle.fd(14.142) #the distance between each square
            your_turtle.right(135)
            your_turtle.down()
        
    main()
    wn.exitonclick()

绘制同心正方形

Drawing concentric squares

python

turtle-graphics