Hello, little turtles!

 import turtle
 wn = turtle.Screen()
 wn.bgcolor("lightgreen")      # Set the window background color
 wn.title("Hello, Tess!")      # Set the window title

 tess = turtle.Turtle()
 tess.color("blue")            # Tell tess to change her color
 tess.pensize(3)               # Tell tess to set her pen width

 tess.forward(50)
 tess.left(120)
 tess.forward(50)

 wn.mainloop()

When we run this program, this new window pops up, and will remain on the screen until we close it.

from：http://www.openbookproject.net/thinkcs/python/english3e/hello_little_turtles.html

import turtle
 wn = turtle.Screen()         # Set up the window and its attributes
 wn.bgcolor("lightgreen")
 wn.title("Tess & Alex")

 tess = turtle.Turtle()       # Create tess and set some attributes
 tess.color("hotpink")
 tess.pensize(5)

 alex = turtle.Turtle()       # Create alex

 tess.forward(80)             # Make tess draw equilateral triangle
 tess.left(120)
 tess.forward(80)
 tess.left(120)
 tess.forward(80)
 tess.left(120)               # Complete the triangle

 tess.right(180)              # Turn tess around
 tess.forward(80)             # Move her away from the origin

 alex.forward(50)             # Make alex draw a square
 alex.left(90)
 alex.forward(50)
 alex.left(90)
 alex.forward(50)
 alex.left(90)
 alex.forward(50)
 alex.left(90)

 wn.mainloop()

A turtle can “stamp” its footprint onto the canvas, and this will remain after the turtle has moved somewhere else. Stamping works, even when the pen is up.

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

tess.penup()                # This is new
size = 20
for i in range(30):
   tess.stamp()             # Leave an impression on the canvas
   size = size + 3          # Increase the size on every iteration
   tess.forward(size)       # Move tess along
   tess.right(24)           #  ...  and turn her

wn.mainloop()

The turtle has a lot more power than we’ve seen so far. The full documentation can be found at http://docs.python.org/py3k/library/turtle.html or within PyScripter, use Help and search for the turtle module.

Here are a couple of new tricks for our turtles:

• We can get a turtle to display text on the canvas at the turtle’s current position. The method to do that is alex.write("Hello").
• We can fill a shape (circle, semicircle, triangle, etc.) with a color. It is a two-step process. First we call the method alex.begin_fill(), then we draw the shape, then we call alex.end_fill().
• We’ve previously set the color of our turtle — we can now also set its fill color, which need not be the same as the turtle and the pen color. We usealex.color("blue","red") to set the turtle to draw in blue, and fill in red.

def draw_bar(t, height):
    """ Get turtle t to draw one bar, of height. """
    t.begin_fill()           # Added this line
    t.left(90)
    t.forward(height)
    t.write("  "+ str(height))
    t.right(90)
    t.forward(40)
    t.right(90)
    t.forward(height)
    t.left(90)
    t.end_fill()             # Added this line
    t.forward(10)

wn = turtle.Screen()         # Set up the window and its attributes
wn.bgcolor("lightgreen")

tess = turtle.Turtle()       # Create tess and set some attributes
tess.color("blue", "red")
tess.pensize(3)

xs = [48,117,200,240,160,260,220]

for a in xs:
    draw_bar(tess, a)

wn.mainloop()