使用Turtle绘制形状

Question

I'm trying to use Python/Turtle to achieve a result like this:

http://i.imgur.com/2eoAB.png

I drew the squares uneven in paint but I mean for them to be even. The squares can be any shape as well depending on the user input (for ex. 5 for polygons).

Here is my code so far:

import turtle
import time
import random

print ("This program draws shapes based on the number you enter in a uniform pattern.")
num_str = input("Enter the side number of the shape you want to draw: ")
if num_str.isdigit():
    squares = int(num_str)

angle = 180 - 180*(squares-2)/squares

turtle.color(random.random(),random.random(), random.random())
turtle.begin_fill()

count = 0
x = -80
y = -80
turtle.setpos(x,y)
turtle.down()

while count < 8:
    x += 50
    y += 50
    turtle.goto(x,y)
    for i in range(squares):
        count += 1
        turtle.forward(20)
        turtle.left(angle)
        turtle.forward(20)      
        print (turtle.pos())

turtle.end_fill()

time.sleep(15)
turtle.bye()

And here is what I get:

http://i.imgur.com/7hAje.png

The error I get is: How can I get it to print out 8 shapes total, instead of only 2, I though the loop would make it repeat 8 times because of the count += 1 < 8?

I thought the loop would change the position of x and y by adding 50, 50 each time and then I would tweak it to give the right coordinates to make the shape I want, but it won't even display all 8 yet?

I've spent a while reconfiguring the code but instead of doing trial and error forever, I figured maybe some help would work, thanks.

I am using Python 3.2.3

Answer 1

If you choose to display a shape with four sides, you're only going to draw two shapes. This is because you're increasing your loop counter once per side for each shape .

This is not a good way to do loops, counters are rarely necessary, and when they are - use enumerate

You want to try something like this.

numshapes = 8
for x in range(numshapes):
  x += 50
  y += 50
  turtle.goto(x,y)
  for i in range(squares):
      turtle.forward(20)
      turtle.left(angle)
      turtle.forward(20)      
      print (turtle.pos())