操纵海龟绘图有着许多的命令,这些命令可以划分为两种:一种为运动命令，一种为画笔控制命令
1. 运动命令:
forward(degree) #向前移动距离degree代表距离
backward(degree) #向后移动距离degree代表距离
right(degree) #向右移动多少度
left(degree) #向左移动多少度
goto(x,y) #将画笔移动到坐标为x,y的位置
stamp() #复制当前图形
speed(speed) #画笔绘制的速度范围[0,10]整数
2. 画笔控制命令:
down() #移动时绘制图形,缺省时也为绘制
up() #移动时不绘制图形
pensize(width) #绘制图形时的宽度
color(colorstring) #绘制图形时的颜色
fillcolor(colorstring) #绘制图形的填充颜色
fill(Ture)
fill(false)
lucy : 梦想照进现实；露茜；青春风采；
draw_flower1.py
import turtle
import math
def p_line(t, n, length, angle):
"""Draws n line segments."""
for i in range(n):
t.fd(length)
t.lt(angle)
def polygon(t, n, length):
"""Draws a polygon with n sides."""
angle = 360/n
p_line(t, n, length, angle)
def arc(t, r, angle):
"""Draws an arc with the given radius and angle."""
arc_length = 2 * math.pi * r * abs(angle) / 360
n = int(arc_length / 4) + 1
step_length = arc_length / n
step_angle = float(angle) / n
# Before starting reduces, making a slight left turn.
t.lt(step_angle/2)
p_line(t, n, step_length, step_angle)
t.rt(step_angle/2)
def petal(t, r, angle):
"""Draws a 花瓣 using two arcs."""
for i in range(2):
arc(t, r, angle)
t.lt(180-angle)
def flower(t, n, r, angle, p):
"""Draws a flower with n petals."""
for i in range(n):
petal(t, r, angle)
t.lt(p/n)
def leaf(t, r, angle, p):
"""Draws a 叶子 and fill it."""
t.begin_fill() # Begin the fill process.
t.down()
flower(t, 1, 40, 80, 180)
t.end_fill()
def main():
window=turtle.Screen() #creat a screen
window.bgcolor("blue")
lucy=turtle.Turtle()
lucy.shape("turtle")
lucy.color("red")
lucy.width(5)
lucy.speed(0)
# Drawing flower
flower(lucy, 10, 40, 100, 360)
# Drawing pedicel
lucy.color("brown")
lucy.rt(90)
lucy.fd(200)
# Drawing leaf
lucy.rt(270)
lucy.color("green")
leaf(lucy, 40, 80, 180)
lucy.ht()
window.exitonclick()
main()
执行结果：
