"""This module contains a code example related to
Think Python, 2nd Edition
by Allen Downey
http://thinkpython2.com
Copyright 2015 Allen Downey
License: http://creativecommons.org/licenses/by/4.0/
"""
from __future__ import print_function, division
import turtle
from polygon import arc
def petal(t, r, angle):
"""Draws a petal using two arcs.
t: Turtle
r: radius of the arcs
angle: angle (degrees) that subtends the arcs
"""
for i in range(2):
arc(t, r, angle)
t.lt(180-angle)
def flower(t, n, r, angle):
"""Draws a flower with n petals.
t: Turtle
n: number of petals
r: radius of the arcs
angle: angle (degrees) that subtends the arcs
"""
for i in range(n):
petal(t, r, angle)
t.lt(360.0/n)
def move(t, length):
"""Move Turtle (t) forward (length) units without leaving a trail.
Leaves the pen down.
"""
t.pu()
t.fd(length)
t.pd()
bob = turtle.Turtle()
# draw a sequence of three flowers, as shown in the book.
move(bob, -100)
flower(bob, 7, 60.0, 60.0)
move(bob, 100)
flower(bob, 10, 40.0, 80.0)
move(bob, 100)
flower(bob, 20, 140.0, 20.0)
bob.hideturtle()
turtle.mainloop()