Updating turtle programs

Author: AllenDowney

code/flower.py

@@ -1,20 +1,19 @@
-"""This module contains code from
-Think Python by Allen B. Downey
-http://thinkpython.com
+"""This module contains a code example related to
 
-Copyright 2012 Allen B. Downey
-License: GNU GPLv3 http://www.gnu.org/licenses/gpl.html
+Think Python, 2nd Edition
+by Allen Downey
+http://thinkpython2.com
 
+Copyright 2015 Allen Downey
+
+License: http://creativecommons.org/licenses/by/4.0/
 """
 
-try:
-    # see if Swampy is installed as a package
-    from swampy.TurtleWorld import *
-except ImportError:
-    # otherwise see if the modules are on the PYTHONPATH
-    from TurtleWorld import *
+from __future__ import print_function, division
+
+import turtle
 
-from polygon import *
+from polygon import arc
 
 
 def petal(t, r, angle):
@@ -26,7 +25,7 @@ def petal(t, r, angle):
     """
     for i in range(2):
         arc(t, r, angle)
-        lt(t, 180-angle)
+        t.lt(180-angle)
 
 
 def flower(t, n, r, angle):
@@ -39,21 +38,19 @@ def flower(t, n, r, angle):
     """
     for i in range(n):
         petal(t, r, angle)
-        lt(t, 360.0/n)
+        t.lt(360.0/n)
 
 
 def move(t, length):
     """Move Turtle (t) forward (length) units without leaving a trail.
     Leaves the pen down.
     """
-    pu(t)
-    fd(t, length)
-    pd(t)
+    t.pu()
+    t.fd(length)
+    t.pd()
 
 
-world = TurtleWorld()
-bob = Turtle()
-bob.delay = 0.01
+bob = turtle.Turtle()
 
 # draw a sequence of three flowers, as shown in the book.
 move(bob, -100)
@@ -65,9 +62,5 @@ def move(t, length):
 move(bob, 100)
 flower(bob, 20, 140.0, 20.0)
 
-die(bob)
-
-# dump the contents of the campus to the file canvas.eps
-world.canvas.dump()
-
-wait_for_user()
+bob.hideturtle()
+turtle.mainloop()

code/koch.py

@@ -1,50 +1,47 @@
-"""This module contains code from
-Think Python by Allen B. Downey
-http://thinkpython.com
+"""This module contains a code example related to
 
-Copyright 2012 Allen B. Downey
-License: GNU GPLv3 http://www.gnu.org/licenses/gpl.html
+Think Python, 2nd Edition
+by Allen Downey
+http://thinkpython2.com
 
+Copyright 2015 Allen Downey
+
+License: http://creativecommons.org/licenses/by/4.0/
 """
 
-try:
-    # see if Swampy is installed as a package
-    from swampy.TurtleWorld import *
-except ImportError:
-    # otherwise see if the modules are on the PYTHONPATH
-    from TurtleWorld import *
+from __future__ import print_function, division
+
+import turtle
 
 
 def koch(t, n):
     """Draws a koch curve with length n."""
-    if n<3:
-        fd(t, n)
+    if n < 10:
+        t.fd(n)
         return
-    m = n/3.0
+    m = n/3
     koch(t, m)
-    lt(t, 60)
+    t.lt(60)
     koch(t, m)
-    rt(t, 120)
+    t.rt(120)
     koch(t, m)
-    lt(t, 60)
+    t.lt(60)
     koch(t, m)
 
 
 def snowflake(t, n):
     """Draws a snowflake (a triangle with a Koch curve for each side)."""
     for i in range(3):
         koch(t, n)
-        rt(t, 120)
+        t.rt(120)
 
 
-world = TurtleWorld()
-bob = Turtle()
-bob.delay = 0
-
-bob.x = -150
-bob.y = 90
-bob.redraw()
+bob = turtle.Turtle()
 
+bob.pu()
+bob.goto(-150, 90)
+bob.pd()
 snowflake(bob, 300)
 
-world.mainloop()
+turtle.mainloop()
+

code/letters.py

@@ -1,19 +1,40 @@
-"""This module contains code from
-Think Python by Allen B. Downey
-http://thinkpython.com
+"""This module contains a code example related to
 
-Copyright 2012 Allen B. Downey
-License: GNU GPLv3 http://www.gnu.org/licenses/gpl.html
+Think Python, 2nd Edition
+by Allen Downey
+http://thinkpython2.com
 
+Copyright 2015 Allen Downey
+
+License: http://creativecommons.org/licenses/by/4.0/
 """
 
-from swampy.TurtleWorld import *
+from __future__ import print_function, division
+
+import turtle
 
 from polygon import circle, arc
 
-# LEVEL 0 PRIMITIVES are provided by World.py.
-# They include fd, bk, lt, rt, pu and pd
+# LEVEL 0 PRIMITIVES 
+# fd, bk, lt, rt, pu and pd
+
+def fd(t, length):
+    t.fd(length)
+
+def bk(t, length):
+    t.bk(length)
 
+def lt(t, angle=90):
+    t.lt(angle)
+
+def rt(t, angle=90):
+    t.rt(angle)
+
+def pd(t):
+    t.pd()
+
+def pu(t):
+    t.pu()
 
 # LEVEL 1 PRIMITIVES are simple combinations of Level 0 primitives.
 # They have no pre- or post-conditions.
@@ -35,7 +56,7 @@ def skip(t, n):
     pd(t)
 
 def stump(t, n, angle=90):
-    """make a vertical line and leave the turtle at the top, facing right"""
+    """Makes a vertical line and leave the turtle at the top, facing right"""
     lt(t)
     fd(t, n)
     rt(t, angle)
@@ -53,20 +74,19 @@ def hollow(t, n):
 # location and direction.
 
 def post(t, n):
-    """make a vertical line and return to the original position"""
+    """Makes a vertical line and return to the original position"""
     lt(t)
     fdbk(t, n)
     rt(t)
 
 def beam(t, n, height):
-    """make a horizontal line at the given height and return."""
+    """Makes a horizontal line at the given height and return."""
     hollow(t, n*height)
     fdbk(t, n)
     hollow(t, -n*height)
 
-
 def hangman(t, n, height):
-    """make a vertical line to the given height and a horizontal line
+    """Makes a vertical line to the given height and a horizontal line
     at the given height and then return.
     This is efficient to implement, and turns out to be useful, but
     it's not so semantically clean."""
@@ -77,7 +97,7 @@ def hangman(t, n, height):
     rt(t)
 
 def diagonal(t, x, y):
-    """make a diagonal line to the given x, y offsets and return"""
+    """Makes a diagonal line to the given x, y offsets and return"""
     from math import atan2, sqrt, pi
     angle = atan2(y, x) * 180 / pi
     dist = sqrt(x**2 + y**2)
@@ -90,7 +110,7 @@ def vshape(t, n, height):
     diagonal(t, n/2, height*n)
 
 def bump(t, n, height):
-    """make a bump with radius n at height*n 
+    """Makes a bump with radius n at height*n 
     """
     stump(t, n*height)
     arc(t, n/2.0, 180)
@@ -264,15 +284,13 @@ def draw_(t, n):
     skip(t, n)
 
 if __name__ == '__main__':
-    world = TurtleWorld()
 
     # create and position the turtle
     size = 20
-    bob = Turtle()
-    bob.delay = 0.01
+    bob = turtle.Turtle()
 
     for f in [draw_h, draw_e, draw_l, draw_l, draw_o]:
         f(bob, size)
         skip(bob, size)
 
-    wait_for_user()
+    turtle.mainloop()

code/pie.py

@@ -1,20 +1,18 @@
-"""This module contains code from
-Think Python by Allen B. Downey
-http://thinkpython.com
+"""This module contains a code example related to
 
-Copyright 2012 Allen B. Downey
-License: GNU GPLv3 http://www.gnu.org/licenses/gpl.html
+Think Python, 2nd Edition
+by Allen Downey
+http://thinkpython2.com
 
+Copyright 2015 Allen Downey
+
+License: http://creativecommons.org/licenses/by/4.0/
 """
 
-import math
+from __future__ import print_function, division
 
-try:
-    # see if Swampy is installed as a package
-    from swampy.TurtleWorld import *
-except ImportError:
-    # otherwise see if the modules are on the PYTHONPATH
-    from TurtleWorld import *
+import math
+import turtle
 
 
 def draw_pie(t, n, r):
@@ -25,9 +23,9 @@ def draw_pie(t, n, r):
     r: length of the radial spokes
     """
     polypie(t, n, r)
-    pu(t)
-    fd(t, r*2 + 10)
-    pd(t)
+    t.pu()
+    t.fd(r*2 + 10)
+    t.pd()
 
 
 def polypie(t, n, r):
@@ -40,7 +38,7 @@ def polypie(t, n, r):
     angle = 360.0 / n
     for i in range(n):
         isosceles(t, r, angle/2)
-        lt(t, angle)
+        t.lt(angle)
 
 
 def isosceles(t, r, angle):
@@ -54,33 +52,28 @@ def isosceles(t, r, angle):
     """
     y = r * math.sin(angle * math.pi / 180)
 
-    rt(t, angle)
-    fd(t, r)
-    lt(t, 90+angle)
-    fd(t, 2*y)
-    lt(t, 90+angle)
-    fd(t, r)
-    lt(t, 180-angle)
+    t.rt(angle)
+    t.fd(r)
+    t.lt(90+angle)
+    t.fd(2*y)
+    t.lt(90+angle)
+    t.fd(r)
+    t.lt(180-angle)
 
 
-# create the world and bob
-world = TurtleWorld()
-bob = Turtle()
-bob.delay = 0
-pu(bob)
-bk(bob, 130)
-pd(bob)
+bob = turtle.Turtle()
+
+bob.pu()
+bob.bk(130)
+bob.pd()
 
 # draw polypies with various number of sides
 size = 40
 draw_pie(bob, 5, size)
 draw_pie(bob, 6, size)
 draw_pie(bob, 7, size)
 draw_pie(bob, 8, size)
-die(bob)
-
-# dump the contents of the campus to the file canvas.eps
-world.canvas.dump()
 
-wait_for_user()
+bob.hideturtle()
+turtle.mainloop()