Python - Conditionals and Recursion(fractal, Koch Curve, snowflake)

Think Python

開発環境

• OS X El Capitan - Apple (OS)
• Emacs (Text Editor)
• Python 3.5 (プログラミング言語)

Think Python (Allen B. Downey (著)、 O'Reilly Media)のChapter 5.(Conditionals and Recursion)のExercises 5-6(No. 1277)を取り組んでみる。

Exercises 5-6(No. 1277)

コード(Emacs)

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import turtle

def koch(t, length):
    if length < 3:
        t.fd(length)
        return
    length /= 3
    koch(t, length)
    t.lt(60)
    koch(t, length)
    t.rt(120)
    koch(t, length)
    t.lt(60)
    koch(t, length)

def snowflake(t, length):
    for _ in range(3):
        koch(t, length)
        t.rt(120)

if __name__ == '__main__':
    t = turtle.Turtle()
    snowflake(t, 100)
    turtle.mainloop()