Sorry I've been quiet for a while, but in the meantime, I did some final
cleanup and I'm thinking the attached version will be what I'll be
submitting.
There are some things we've discussed that I decided to leave out, not
necessarily because they shouldn't be done, but because I think we
couldn't get them done in time for the next release of Python. These are:
1. The decorator generated docstrings. Cool as the idea was, they make
the source code ugly and would be distracting to newbies actually
reading the code. Besides, in an unscientific survey of Python
developers, the consensus was that decorators were intended for bigger
game.
2. any changes to the circle drawing/filling. It clearly doesn't work
right, but fixing it without breaking any old code will take some doing.
3. the speed issues addressed a couple weeks ago. Again, it seems like a
good idea, but would involve rewriting several things.
Otherwise:
I left the speed() method as taking a string parameter (one of 5
choices). The delay() method can be used to give finer control.
I added docstrings to the some utility functions. Thanks to Toby for the
enhanced docstrings everywhere else.
I've modified one of Gregor's files to serve as a demo and test of both
the old module and the new one. It is attached as demo.py and
enhancements are welcome.
So have a look and see if you can live with this. Let me know what your
reactions are.
Cheers,
Vern
--
This time for sure!
-Bullwinkle J. Moose
-----------------------------
Vern Ceder, Director of Technology
Canterbury School, 3210 Smith Road, Ft Wayne, IN 46804
[EMAIL PROTECTED]; 260-436-0746; FAX: 260-436-5137
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# LogoMation-like turtle graphics
"""
Turtle graphics is a popular way for introducing programming to
kids. It was part of the original Logo programming language developed
by Wally Feurzig and Seymour Papert in 1966.
Imagine a robotic turtle starting at (0, 0) in the x-y plane. Give it
the command turtle.forward(15), and it moves (on-screen!) 15 pixels in
the direction it is facing, drawing a line as it moves. Give it the
command turtle.left(25), and it rotates in-place 25 degrees clockwise.
By combining together these and similar commands, intricate shapes and
pictures can easily be drawn.
"""
from math import * # Also for export
import Tkinter
speeds = ['fastest', 'fast', 'normal', 'slow', 'slowest']
class Error(Exception):
pass
class RawPen:
def __init__(self, canvas):
self._canvas = canvas
self._items = []
self._tracing = 1
self._arrow = 0
self._delay = 10 # default delay for drawing
self.degrees()
self.reset()
def degrees(self, fullcircle=360.0):
""" Set angle measurement units to degrees.
Example:
>>> turtle.degrees()
"""
self._fullcircle = fullcircle
self._invradian = pi / (fullcircle * 0.5)
def radians(self):
""" Set the angle measurement units to radians.
Example:
>>> turtle.radians()
"""
self.degrees(2.0*pi)
def reset(self):
"""Clear the screen, re-center the pen, and set variables to
the default values.
Example:
>>> turtle.position()
[0.0, -22.0]
>>> turtle.heading()
100.0
>>> turtle.reset()
>>> turtle.position()
[0.0, 0.0]
>>> turtle.heading()
0.0
"""
canvas = self._canvas
self._canvas.update()
width = canvas.winfo_width()
height = canvas.winfo_height()
if width <= 1:
width = canvas['width']
if height <= 1:
height = canvas['height']
self._origin = float(width)/2.0, float(height)/2.0
self._position = self._origin
self._angle = 0.0
self._drawing = 1
self._width = 1
self._color = "black"
self._filling = 0
self._path = []
self._tofill = []
self.clear()
canvas._root().tkraise()
def clear(self):
""" Clear the screen. The turtle does not move.
Example:
>>> turtle.clear()
"""
self.fill(0)
canvas = self._canvas
items = self._items
self._items = []
for item in items:
canvas.delete(item)
self._delete_turtle()
self._draw_turtle()
def tracer(self, flag):
"""Set tracing on if flag is True, and off if it is False.
Tracing means line are drawn more slowly, with an
animation of an arrow along the line.
Example:
>>> turtle.tracer(False) # turns off Tracer
"""
self._tracing = flag
if not self._tracing:
self._delete_turtle()
self._draw_turtle()
def forward(self, distance):
""" Go forward distance steps.
Example:
>>> turtle.position()
[0.0, 0.0]
>>> turtle.forward(25)
>>> turtle.position()
[25.0, 0.0]
>>> turtle.forward(-75)
>>> turtle.position()
[-50.0, 0.0]
"""
x0, y0 = start = self._position
x1 = x0 + distance * cos(self._angle*self._invradian)
y1 = y0 - distance * sin(self._angle*self._invradian)
self._goto(x1, y1)
def backward(self, distance):
""" Go backwards distance steps.
The turtle's heading does not change.
Example:
>>> turtle.position()
[0.0, 0.0]
>>> turtle.backward(30)
>>> turtle.position()
[-30.0, 0.0]
"""
self.forward(-distance)
def left(self, angle):
""" Turn left angle units (units are by default degrees,
but can be set via the degrees() and radians() functions.)
When viewed from above, the turning happens in-place around
its front tip.
Example:
>>> turtle.heading()
22
>>> turtle.left(45)
>>> turtle.heading()
67.0
"""
self._angle = (self._angle + angle) % self._fullcircle
self._draw_turtle()
def right(self, angle):
""" Turn right angle units (units are by default degrees,
but can be set via the degrees() and radians() functions.)
When viewed from above, the turning happens in-place around
its front tip.
Example:
>>> turtle.heading()
22
>>> turtle.right(45)
>>> turtle.heading()
337.0
"""
self.left(-angle)
def up(self):
"""Pull the pen up -- no drawing when moving.
Example:
>>> turtle.up()
"""
self._drawing = 0
def down(self):
"""Put the pen down -- draw when moving.
Example:
>>> turtle.down()
"""
self._drawing = 1
def width(self, width):
""" Set the line to thickness to width.
Example:
>>> turtle.width(10)
"""
self._width = float(width)
def color(self, *args):
""" Set the pen color.
Three input formats are allowed:
color(s)
s is a Tk specification string, such as "red" or "yellow"
color((r, g, b))
*a tuple* of r, g, and b, which represent, an RGB color,
and each of r, g, and b are in the range [0..1]
color(r, g, b)
r, g, and b represent an RGB color, and each of r, g, and b
are in the range [0..1]
Example:
>>> turtle.color('brown')
>>> tup = (0.2, 0.8, 0.55)
>>> turtle.color(tup)
>>> turtle.color(0, .5, 0)
"""
if not args:
raise Error, "no color arguments"
if len(args) == 1:
color = args[0]
if type(color) == type(""):
# Test the color first
try:
id = self._canvas.create_line(0, 0, 0, 0, fill=color)
except Tkinter.TclError:
raise Error, "bad color string: %r" % (color,)
self._set_color(color)
return
try:
r, g, b = color
except:
raise Error, "bad color sequence: %r" % (color,)
else:
try:
r, g, b = args
except:
raise Error, "bad color arguments: %r" % (args,)
assert 0 <= r <= 1
assert 0 <= g <= 1
assert 0 <= b <= 1
x = 255.0
y = 0.5
self._set_color("#%02x%02x%02x" % (int(r*x+y), int(g*x+y), int(b*x+y)))
def _set_color(self,color):
self._color = color
self._draw_turtle()
def write(self, text, move=False):
""" Write text at the current pen position.
If move is true, the pen is moved to the bottom-right corner
of the text. By default, move is False.
Example:
>>> turtle.write('The race is on!')
>>> turtle.write('Home = (0, 0)', True)
"""
x, y = self._position
x = x-1 # correction -- calibrated for Windows
item = self._canvas.create_text(x, y,
text=str(text), anchor="sw",
fill=self._color)
self._items.append(item)
if move:
x0, y0, x1, y1 = self._canvas.bbox(item)
self._goto(x1, y1)
self._draw_turtle()
def fill(self, flag):
""" Call fill(1) before drawing the shape you want to fill, and
fill(0) when done.
Example:
>>> turtle.fill(1)
>>> turtle.forward(100)
>>> turtle.left(90)
>>> turtle.forward(100)
>>> turtle.left(90)
>>> turtle.forward(100)
>>> turtle.left(90)
>>> turtle.forward(100)
>>> turtle.fill(0)
"""
if self._filling:
path = tuple(self._path)
smooth = self._filling < 0
if len(path) > 2:
item = self._canvas._create('polygon', path,
{'fill': self._color,
'smooth': smooth})
self._items.append(item)
if self._tofill:
for item in self._tofill:
self._canvas.itemconfigure(item, fill=self._color)
self._items.append(item)
self._path = []
self._tofill = []
self._filling = flag
if flag:
self._path.append(self._position)
self.forward(0)
def begin_fill(self):
""" Called just before drawing a shape to be filled.
Example:
>>> turtle.begin_fill()
>>> turtle.forward(100)
>>> turtle.left(90)
>>> turtle.forward(100)
>>> turtle.left(90)
>>> turtle.forward(100)
>>> turtle.left(90)
>>> turtle.forward(100)
>>> turtle.end_fill()
"""
self.fill(1)
def end_fill(self):
""" Called after drawing a shape to be filled.
Example:
>>> turtle.begin_fill()
>>> turtle.forward(100)
>>> turtle.left(90)
>>> turtle.forward(100)
>>> turtle.left(90)
>>> turtle.forward(100)
>>> turtle.left(90)
>>> turtle.forward(100)
>>> turtle.end_fill()
"""
self.fill(0)
def circle(self, radius, extent=None):
""" Draw a circle with given radius.
The center is radius units left of the turtle; extent
determines which part of the circle is drawn. If not given,
the entire circle is drawn.
If extent is not a full circle, one endpoint of the arc is the
current pen position. The arc is drawn in a counter clockwise
direction if radius is positive, otherwise in a clockwise
direction. In the process, the direction of the turtle is
changed by the amount of the extent.
>>> turtle.circle(50)
>>> turtle.circle(120, 180) # half a circle
"""
if extent is None:
extent = self._fullcircle
x0, y0 = self._position
xc = x0 - radius * sin(self._angle * self._invradian)
yc = y0 - radius * cos(self._angle * self._invradian)
if radius >= 0.0:
start = self._angle - 90.0
else:
start = self._angle + 90.0
extent = -extent
if self._filling:
if abs(extent) >= self._fullcircle:
item = self._canvas.create_oval(xc-radius, yc-radius,
xc+radius, yc+radius,
width=self._width,
outline="")
self._tofill.append(item)
item = self._canvas.create_arc(xc-radius, yc-radius,
xc+radius, yc+radius,
style="chord",
start=start,
extent=extent,
width=self._width,
outline="")
self._tofill.append(item)
if self._drawing:
if abs(extent) >= self._fullcircle:
item = self._canvas.create_oval(xc-radius, yc-radius,
xc+radius, yc+radius,
width=self._width,
outline=self._color)
self._items.append(item)
item = self._canvas.create_arc(xc-radius, yc-radius,
xc+radius, yc+radius,
style="arc",
start=start,
extent=extent,
width=self._width,
outline=self._color)
self._items.append(item)
angle = start + extent
x1 = xc + abs(radius) * cos(angle * self._invradian)
y1 = yc - abs(radius) * sin(angle * self._invradian)
self._angle = (self._angle + extent) % self._fullcircle
self._position = x1, y1
if self._filling:
self._path.append(self._position)
self._draw_turtle()
def heading(self):
""" Returns the turtle's current heading.
Example:
>>> turtle.heading()
67.0
"""
return self._angle
def setheading(self, angle):
""" Set the turtle facing the given angle.
Here are some common directions in degrees:
0 - east
90 - north
180 - west
270 - south
Example:
>>> turtle.setheading(90)
>>> turtle.heading()
90
>>> turtle.setheading(128)
>>> turtle.heading()
128
"""
self._angle = angle
self._draw_turtle()
def window_width(self):
""" Returns the width of the turtle window.
Example:
>>> turtle.window_width()
640
"""
width = self._canvas.winfo_width()
if width <= 1: # the window isn't managed by a geometry manager
width = self._canvas['width']
return width
def window_height(self):
""" Returns the height of the turtle window.
Example:
>>> turtle.window_height()
768
"""
height = self._canvas.winfo_height()
if height <= 1: # the window isn't managed by a geometry manager
height = self._canvas['height']
return height
def position(self):
""" Returns the current (x, y) location of the turtle.
Example:
>>> turtle.position()
[0.0, 240.0]
"""
x0, y0 = self._origin
x1, y1 = self._position
return [x1-x0, -y1+y0]
def setx(self, xpos):
""" Sets the turtle's x coordinate to be xpos.
Example:
>>> turtle.position()
[10.0, 240.0]
>>> turtle.setx(10)
>>> turtle.position()
[10.0, 240.0]
"""
x0, y0 = self._origin
x1, y1 = self._position
self._goto(x0+xpos, y1)
def sety(self, ypos):
""" Sets the turtle's y coordinate to be ypos.
Example:
>>> turtle.position()
[0.0, 0.0]
>>> turtle.sety(-22)
>>> turtle.position()
[0.0, -22.0]
"""
x0, y0 = self._origin
x1, y1 = self._position
self._goto(x1, y0-ypos)
def towards(self, *args):
"""Returns the angle, which corresponds to the line
from turtle-position to point (x,y).
Argument can be two coordinates or one pair of coordinates
or a RawPen/Pen instance.
Example:
>>> turtle.position()
[10.0, 10.0]
>>> turtle.towards(0,0)
225.0
"""
if len(args) == 2:
x, y = args
else:
arg = args[0]
if isinstance(arg, RawPen):
x, y = arg.position()
else:
x, y = arg
x0, y0 = self.position()
dx = x - x0
dy = y - y0
return (atan2(dy,dx) / self._invradian) % self._fullcircle
def goto(self, *args):
""" Goto the given point.
If the pen is down, then a line will be drawn. The turtle's
orientation does not change.
Two input formats are accepted:
goto(x, y)
go to point (x, y)
goto((x, y))
go to point (x, y)
Example:
>>> turtle.position()
[0.0, 0.0]
>>> turtle.goto(50, -45)
>>> turtle.position()
[50.0, -45.0]
"""
if len(args) == 1:
try:
x, y = args[0]
except:
raise Error, "bad point argument: %r" % (args[0],)
else:
try:
x, y = args
except:
raise Error, "bad coordinates: %r" % (args[0],)
x0, y0 = self._origin
self._goto(x0+x, y0-y)
def _goto(self, x1, y1):
x0, y0 = self._position
self._position = map(float, (x1, y1))
if self._filling:
self._path.append(self._position)
if self._drawing:
if self._tracing:
dx = float(x1 - x0)
dy = float(y1 - y0)
distance = hypot(dx, dy)
nhops = int(distance)
item = self._canvas.create_line(x0, y0, x0, y0,
width=self._width,
capstyle="round",
fill=self._color)
try:
for i in range(1, 1+nhops):
x, y = x0 + dx*i/nhops, y0 + dy*i/nhops
self._canvas.coords(item, x0, y0, x, y)
self._draw_turtle((x,y))
self._canvas.update()
self._canvas.after(self._delay)
# in case nhops==0
self._canvas.coords(item, x0, y0, x1, y1)
self._canvas.itemconfigure(item, arrow="none")
except Tkinter.TclError:
# Probably the window was closed!
return
else:
item = self._canvas.create_line(x0, y0, x1, y1,
width=self._width,
capstyle="round",
fill=self._color)
self._items.append(item)
self._draw_turtle()
def speed(self, speed):
""" Set the turtle's speed.
speed must one of these five strings:
'fastest' is a 0 ms delay
'fast' is a 5 ms delay
'normal' is a 10 ms delay
'slow' is a 15 ms delay
'slowest' is a 20 ms delay
Example:
>>> turtle.speed('slow')
"""
try:
speed = speed.strip().lower()
self._delay = speeds.index(speed) * 5
except:
raise ValueError, "%r is not a valid speed. speed must be one of %s" % (speed, speeds)
def delay(self, delay):
""" Sets the drawing delay in milliseconds.
Example:
>>> turtle.delay(15)
"""
if int(delay) < 0:
raise ValueError, "delay must be greater than or equal to 0"
self._delay = int(delay)
def _draw_turtle(self, position=[]):
if not self._tracing:
return
if position == []:
position = self._position
x,y = position
distance = 8
dx = distance * cos(self._angle*self._invradian)
dy = distance * sin(self._angle*self._invradian)
self._delete_turtle()
self._arrow = self._canvas.create_line(x-dx,y+dy,x,y,
width=self._width,
arrow="last",
capstyle="round",
fill=self._color)
self._canvas.update()
def _delete_turtle(self):
if self._arrow != 0:
self._canvas.delete(self._arrow)
self._arrow = 0
_root = None
_canvas = None
_pen = None
_width = 0.50 # 50% of window for width
_height = 0.75 # 75% of window for height
_startx = None
_starty = None
_title = "Turtle Graphics" # default title
class Pen(RawPen):
def __init__(self):
global _root, _canvas
if _root is None:
_root = Tkinter.Tk()
_root.wm_protocol("WM_DELETE_WINDOW", self._destroy)
_root.title(_title)
if _canvas is None:
# XXX Should have scroll bars
_canvas = Tkinter.Canvas(_root, background="white")
_canvas.pack(expand=1, fill="both")
setup(width=_width, height= _height, startx=_startx, starty=_starty)
RawPen.__init__(self, _canvas)
def _destroy(self):
global _root, _canvas, _pen
root = self._canvas._root()
if root is _root:
_pen = None
_root = None
_canvas = None
root.destroy()
def _getpen():
global _pen
if not _pen:
_pen = Pen()
return _pen
class Turtle(Pen):
pass
def degrees(): _getpen().degrees()
def radians(): _getpen().radians()
def reset(): _getpen().reset()
def clear(): _getpen().clear()
def tracer(flag): _getpen().tracer(flag)
def forward(distance): _getpen().forward(distance)
def backward(distance): _getpen().backward(distance)
def left(angle): _getpen().left(angle)
def right(angle): _getpen().right(angle)
def up(): _getpen().up()
def down(): _getpen().down()
def width(width): _getpen().width(width)
def color(*args): _getpen().color(*args)
def write(arg, move=0): _getpen().write(arg, move)
def fill(flag): _getpen().fill(flag)
def begin_fill(): _getpen().begin_fill()
def end_fill(): _getpen.end_fill()
def circle(radius, extent=None): _getpen().circle(radius, extent)
def goto(*args): _getpen().goto(*args)
def heading(): return _getpen().heading()
def setheading(angle): _getpen().setheading(angle)
def position(): return _getpen().position()
def window_width(): return _getpen().window_width()
def window_height(): return _getpen().window_height()
def setx(xpos): _getpen().setx(xpos)
def sety(ypos): _getpen().sety(ypos)
def towards(*args): return _getpen().towards(*args)
def done(): _root.mainloop()
def delay(delay): return _getpen().delay(delay)
def speed(speed): return _getpen().speed(speed)
def setup(**geometry):
""" Sets the size and position of the main window.
Keywords are width, height, startx and starty
width: either a size in pixels or a fraction of the screen.
Default is 50% of screen.
height: either the height in pixels or a fraction of the screen.
Default is 75% of screen.
Setting either width or height to None before drawing will force
use of default geometry as in older versions of turtle.py
startx: starting position in pixels from the left edge of the screen.
Default is to center window. Setting startx to None is the default
and centers window horizontally on screen.
starty: starting position in pixels from the top edge of the screen.
Default is to center window. Setting starty to None is the default
and centers window vertically on screen.
Examples:
>>> setup (width=200, height=200, startx=0, starty=0)
sets window to 200x200 pixels, in upper left of screen
>>> setup(width=.75, height=0.5, startx=None, starty=None)
sets window to 75% of screen by 50% of screen and centers
>>> setup(width=None)
forces use of default geometry as in older versions of turtle.py
"""
global _width, _height, _startx, _starty
width = geometry.get('width',_width)
if width >= 0 or width == None:
_width = width
else:
raise ValueError, "width can not be less than 0"
height = geometry.get('height',_height)
if height >= 0 or height == None:
_height = height
else:
raise ValueError, "height can not be less than 0"
startx = geometry.get('startx', _startx)
if startx >= 0 or startx == None:
_startx = _startx
else:
raise ValueError, "startx can not be less than 0"
starty = geometry.get('starty', _starty)
if starty >= 0 or starty == None:
_starty = starty
else:
raise ValueError, "startx can not be less than 0"
if _root and _width and _height:
if 0 < _width <= 1:
_width = _root.winfo_screenwidth() * +width
if 0 < _height <= 1:
_height = _root.winfo_screenheight() * _height
# center window on screen
if _startx is None:
_startx = (_root.winfo_screenwidth() - _width) / 2
if _starty is None:
_starty = (_root.winfo_screenheight() - _height) / 2
_root.geometry("%dx%d+%d+%d" % (_width, _height, _startx, _starty))
def title(title):
""" set the window title.
By default this is set to 'Turtle Graphics'
Example:
>>> title("My Window")
"""
global _title
_title = title
def demo():
reset()
tracer(1)
up()
backward(100)
down()
# draw 3 squares; the last filled
width(3)
for i in range(3):
if i == 2:
fill(1)
for j in range(4):
forward(20)
left(90)
if i == 2:
color("maroon")
fill(0)
up()
forward(30)
down()
width(1)
color("black")
# move out of the way
tracer(0)
up()
right(90)
forward(100)
right(90)
forward(100)
right(180)
down()
# some text
write("startstart", 1)
write("start", 1)
color("red")
# staircase
for i in range(5):
forward(20)
left(90)
forward(20)
right(90)
# filled staircase
fill(1)
for i in range(5):
forward(20)
left(90)
forward(20)
right(90)
fill(0)
# more text
write("end")
if __name__ == '__main__':
done()
if __name__ == '__main__':
demo()
from turtle import *
from Tkinter import mainloop
from time import sleep
def demo1():
# demo des alten turtle-Moduls
reset()
tracer(1)
up()
backward(100)
down()
# draw 3 squares; the last filled
width(3)
for i in range(3):
if i == 2:
fill(1)
for j in range(4):
forward(20)
left(90)
if i == 2:
color("maroon")
fill(0)
up()
forward(30)
down()
width(1)
color("black")
# move out of the way
tracer(0)
up()
right(90)
forward(100)
right(90)
forward(100)
right(180)
down()
# some text
write("startstart", 1)
write("start", 1)
color("red")
# staircase
for i in range(5):
forward(20)
left(90)
forward(20)
right(90)
# filled staircase
fill(1)
for i in range(5):
forward(20)
left(90)
forward(20)
right(90)
fill(0)
# more text
write("wait a moment...")
tracer(1)
def demo2():
# einige weitere und einige neue features
speed('fast')
## st()
width(3)
setheading(towards(0,0))
x,y = position()
r = (x**2+y**2)**.5/2.0
right(90)
pendown = True
for i in range(18):
if pendown:
up()
pendown = False
else:
down()
pendown = True
circle(r,10)
sleep(2)
reset()
left(90)
l = 10
color("green")
width(3)
left(180)
sp = 5
for i in range(-2,16):
if i > 0:
color(1.0-0.05*i,0,0.05*i)
fill(1)
color("green")
for j in range(3):
forward(l)
left(120)
l += 10
left(15)
if sp > 0:
sp = sp-1
speed(speeds[sp])
color(0.25,0,0.75)
fill(0)
color("green")
left(120)
up()
forward(70)
right(30)
down()
color("red")
speed('fastest')
fill(1)
for i in range(4):
circle(50,90)
right(90)
forward(30)
right(90)
color("yellow")
fill(0)
color("red")
left(90)
up(); forward(30); down(); # setshape(1)
## tri = turtles()[0]
turtle=Pen()
## turtle.setshape(1)
#### turtle.mode("logo")
turtle.reset()
turtle.left(90)
turtle.speed('normal')
turtle.up()
turtle.goto(280,40)
turtle.left(24)
turtle.down()
turtle.speed('normal')
turtle.color("blue")
turtle.width(2)
speed('fastest')
## setheading(towards(*turtle.position())) ## for simple towards
setheading(towards(turtle))
while ( abs(position()[0]-turtle.position()[0])>4 or
abs(position()[1]-turtle.position()[1])>4):
turtle.forward(3.5)
turtle.left(0.6)
## setheading(towards(*turtle.position()))
setheading(towards(turtle))
forward(4)
write("CAUGHT! ", move=True)
demo1()
try:
demo2()
except:
pass
mainloop()
