"turtle" --- Grafika żółwia
***************************

**Kod źródłowy:** Lib/turtle.py

======================================================================


Wprowadzenie
============

Turtle graphics is a popular way for introducing programming to kids.
It was part of the original Logo programming language developed by
Wally Feurzeig, Seymour Papert and Cynthia Solomon in 1967.

Wyobraźmy sobie żółwia-robota rozpoczynającego ruch w punkcie (0, 0)
na płaszczyźnie x-y.  Po "import turtle", wydaj polecenie
"turtle.forward(15)", a przesunie się (na ekranie!) o 15 pikseli w
kierunku, w którym jest zwrócony, rysując linię podczas ruchu.  Wydaj
polecenie "turtle.right(25)", a obróci się w miejscu o 25 stopni
zgodnie z ruchem wskazówek zegara.


Turtle star
^^^^^^^^^^^

Żółw może rysować skomplikowane kształty za pomocą programów, które
powtarzają proste ruchy.

[obraz]

   from turtle import *
   color('red', 'yellow')
   begin_fill()
   while True:
       forward(200)
       left(170)
       if abs(pos()) < 1:
           break
   end_fill()
   done()

By combining together these and similar commands, intricate shapes and
pictures can easily be drawn.

The "turtle" module is an extended reimplementation of the same-named
module from the Python standard distribution up to version Python 2.5.

It tries to keep the merits of the old turtle module and to be
(nearly) 100% compatible with it.  This means in the first place to
enable the learning programmer to use all the commands, classes and
methods interactively when using the module from within IDLE run with
the "-n" switch.

The turtle module provides turtle graphics primitives, in both object-
oriented and procedure-oriented ways.  Because it uses "tkinter" for
the underlying graphics, it needs a version of Python installed with
Tk support.

The object-oriented interface uses essentially two+two classes:

1. The "TurtleScreen" class defines graphics windows as a playground
   for the drawing turtles.  Its constructor needs a "tkinter.Canvas"
   or a "ScrolledCanvas" as argument.  It should be used when "turtle"
   is used as part of some application.

   The function "Screen()" returns a singleton object of a
   "TurtleScreen" subclass. This function should be used when "turtle"
   is used as a standalone tool for doing graphics. As a singleton
   object, inheriting from its class is not possible.

   All methods of TurtleScreen/Screen also exist as functions, i.e. as
   part of the procedure-oriented interface.

2. "RawTurtle" (alias: "RawPen") defines Turtle objects which draw on
   a "TurtleScreen".  Its constructor needs a Canvas, ScrolledCanvas
   or TurtleScreen as argument, so the RawTurtle objects know where to
   draw.

   Derived from RawTurtle is the subclass "Turtle" (alias: "Pen"),
   which draws on "the" "Screen" instance which is automatically
   created, if not already present.

   All methods of RawTurtle/Turtle also exist as functions, i.e. part
   of the procedure-oriented interface.

The procedural interface provides functions which are derived from the
methods of the classes "Screen" and "Turtle".  They have the same
names as the corresponding methods.  A screen object is automatically
created whenever a function derived from a Screen method is called.
An (unnamed) turtle object is automatically created whenever any of
the functions derived from a Turtle method is called.

To use multiple turtles on a screen one has to use the object-oriented
interface.

Informacja:

  W poniższej dokumentacji podano listę argumentów dla funkcji.
  Metody, oczywiście, mają dodatkowy pierwszy argument *self*, który
  jest tutaj pominięty.


Overview of available Turtle and Screen methods
===============================================


Metody żółwia
-------------

Ruch żółwia
   Przesuwanie i rysowanie
         "forward()" | "fd()"
         "backward()" | "bk()" | "back()"
         "right()" | "rt()"
         "left()" | "lt()"
         "goto()" | "setpos()" | "setposition()"
         "setx()"
         "sety()"
         "setheading()" | "seth()"
         "home()"
         "circle()"
         "dot()"
         "stamp()"
         "clearstamp()"
         "clearstamps()"
         "undo()"
         "speed()"

   Pobieranie stanu żółwia
         "position()" | "pos()"
         "towards()"
         "xcor()"
         "ycor()"
         "heading()"
         "distance()"

   Ustawienia i pomiary
         "degrees()"
         "radians()"

Kontrola pióra
   Stan rysowania
         "pendown()" | "pd()" | "down()"
         "penup()" | "pu()" | "up()"
         "pensize()" | "width()"
         "pen()"
         "isdown()"

   Kontrola koloru
         "color()"
         "pencolor()"
         "fillcolor()"

   Wypełnienie
         "filling()"
         "begin_fill()"
         "end_fill()"

   Więcej kontroli rysowania
         "reset()"
         "clear()"
         "write()"

Stan żółwia
   Widoczność
         "showturtle()" | "st()"
         "hideturtle()" | "ht()"
         "isvisible()"

   Wygląd
         "shape()"
         "resizemode()"
         "shapesize()" | "turtlesize()"
         "shearfactor()"
         "settiltangle()"
         "tiltangle()"
         "tilt()"
         "shapetransform()"
         "get_shapepoly()"

Korzystanie ze zdarzeń
      "onclick()"
      "onrelease()"
      "ondrag()"

Specjalne metody żółwi
      "begin_poly()"
      "end_poly()"
      "get_poly()"
      "clone()"
      "getturtle()" | "getpen()"
      "getscreen()"
      "setundobuffer()"
      "undobufferentries()"


Metody TurtleScreen/Screen
--------------------------

Kontrola okna
      "bgcolor()"
      "bgpic()"
      "clearscreen()"
      "resetscreen()"
      "screensize()"
      "setworldcoordinates()"

Kontrola animacji
      "delay()"
      "tracer()"
      "update()"

Korzystanie ze zdarzeń ekranowych
      "listen()"
      "onkey()" | "onkeyrelease()"
      "onkeypress()"
      "onclick()" | "onscreenclick()"
      "ontimer()"
      "mainloop()" | "done()"

Ustawienia i metody specjalne
      "mode()"
      "colormode()"
      "getcanvas()"
      "getshapes()"
      "register_shape()" | "addshape()"
      "turtles()"
      "window_height()"
      "window_width()"

Metody wprowadzania danych
      "textinput()"
      "numinput()"

Metody specyficzne dla klasy Screen
      "bye()"
      "exitonclick()"
      "setup()"
      "title()"


Metody RawTurtle/Turtle i odpowiadające im funkcje
==================================================

Większość przykładów w tej sekcji odnosi się do instancji klasy Turtle
o nazwie "turtle".


Ruch żółwia
-----------

turtle.forward(distance)
turtle.fd(distance)

   Parametry:
      **distance** -- liczba (całkowita lub zmiennoprzecinkowa)

   Przesuwa żółwia do przodu o określony *dystans*, w kierunku, w
   którym żółw jest skierowany.

      >>> turtle.position()
      (0.00,0.00)
      >>> turtle.forward(25)
      >>> turtle.position()
      (25.00,0.00)
      >>> turtle.forward(-75)
      >>> turtle.position()
      (-50.00,0.00)

turtle.back(distance)
turtle.bk(distance)
turtle.backward(distance)

   Parametry:
      **distance** -- liczba

   Przesuwa żółwia do tyłu o *dystans*, w kierunku przeciwnym do
   kierunku, w którym żółw jest skierowany. Nie zmienia kierunku
   żółwia.

      >>> turtle.position()
      (0.00,0.00)
      >>> turtle.backward(30)
      >>> turtle.position()
      (-30.00,0.00)

turtle.right(angle)
turtle.rt(angle)

   Parametry:
      **angle** -- liczba (całkowita lub zmiennoprzecinkowa)

   Obraca żółwia w prawo o jednostki *kąta*.  (Jednostki to domyślnie
   stopnie, ale można je ustawić za pomocą funkcji "degrees()" i
   "radians()".) Orientacja kąta zależy od trybu żółwia, patrz
   "mode()".

      >>> turtle.heading()
      22.0
      >>> turtle.right(45)
      >>> turtle.heading()
      337.0

turtle.left(angle)
turtle.lt(angle)

   Parametry:
      **angle** -- liczba (całkowita lub zmiennoprzecinkowa)

   Obraca żółwia w lewo o jednostki *kąta*.  (Jednostki to domyślnie
   stopnie, ale można je ustawić za pomocą funkcji "degrees()" i
   "radians()".) Orientacja kąta zależy od trybu żółwia, patrz
   "mode()".

      >>> turtle.heading()
      22.0
      >>> turtle.left(45)
      >>> turtle.heading()
      67.0

turtle.goto(x, y=None)
turtle.setpos(x, y=None)
turtle.setposition(x, y=None)

   Parametry:
      * **x** -- liczba lub para/wektor liczb

      * **y** -- liczba lub "None"

   Jeśli *y* to "None", *x* musi być parą współrzędnych lub obiektem
   "Vec2D" (np. zwróconym przez "pos()").

   Przesuwa żółwia do pozycji bezwzględnej. Jeśli pióro jest
   opuszczone, rysuje linię. Nie zmienia orientacji żółwia.

       >>> tp = turtle.pos()
       >>> tp
       (0.00,0.00)
       >>> turtle.setpos(60,30)
       >>> turtle.pos()
       (60.00,30.00)
       >>> turtle.setpos((20,80))
       >>> turtle.pos()
       (20.00,80.00)
       >>> turtle.setpos(tp)
       >>> turtle.pos()
       (0.00,0.00)

turtle.setx(x)

   Parametry:
      **x** -- liczba (całkowita lub zmiennoprzecinkowa)

   Ustawia pierwszą współrzędną żółwia na *x*, drugą pozostawiając bez
   zmian.

      >>> turtle.position()
      (0.00,240.00)
      >>> turtle.setx(10)
      >>> turtle.position()
      (10.00,240.00)

turtle.sety(y)

   Parametry:
      **y** -- liczba (całkowita lub zmiennoprzecinkowa)

   Ustawia drugą współrzędną żółwia na *y*, pozostawiąc pierwszą
   współrzędną bez zmian.

      >>> turtle.position()
      (0.00,40.00)
      >>> turtle.sety(-10)
      >>> turtle.position()
      (0.00,-10.00)

turtle.setheading(to_angle)
turtle.seth(to_angle)

   Parametry:
      **to_angle** -- liczba (całkowita lub zmiennoprzecinkowa)

   Ustawia orientację żółwia na *to_angle*.  Oto kilka często
   używanych kierunków w stopniach:

   +---------------------+----------------------+
   | tryb standardowy    | tryb logo            |
   |=====================|======================|
   | 0 – wschód          | 0 – północ           |
   +---------------------+----------------------+
   | 90 – północ         | 90 – wschód          |
   +---------------------+----------------------+
   | 180 – zachód        | 180 – południe       |
   +---------------------+----------------------+
   | 270 – południe      | 270 – zachód         |
   +---------------------+----------------------+

      >>> turtle.setheading(90)
      >>> turtle.heading()
      90.0

turtle.home()

   Przesuwa żółwia do punktu początkowego – współrzędne (0,0) – i
   ustawia jego kurs na orientację początkową (która zależy od trybu,
   patrz "mode()").

      >>> turtle.heading()
      90.0
      >>> turtle.position()
      (0.00,-10.00)
      >>> turtle.home()
      >>> turtle.position()
      (0.00,0.00)
      >>> turtle.heading()
      0.0

turtle.circle(radius, extent=None, steps=None)

   Parametry:
      * **radius** -- liczba

      * **extent** -- liczba (lub "None")

      * **steps** -- liczba całkowita (lub "None")

   Rysuje okrąg o podanym *promieniu*. Środek znajduje się w
   odległości *radius* na lewo od żółwia; *extent* – kąt – określa,
   która część okręgu zostanie narysowana. Jeśli *extent* nie jest
   podany, rysowany jest cały okrąg. Jeśli *extent* nie jest pełnym
   okręgiem, jednym z punktów końcowych łuku jest bieżąca pozycja
   pióra. Rysuje łuk w kierunku przeciwnym do ruchu wskazówek zegara,
   jeśli *radius* jest dodatni, w przeciwnym razie w kierunku zgodnym
   z ruchem wskazówek zegara. Kierunek żółwia jest zmieniany o wartość
   *extent*.

   Ponieważ okrąg jest przybliżany przez wpisany wielokąt foremny,
   *steps* określa liczbę kroków do użycia. Jeśli nie zostanie podana,
   zostanie obliczona automatycznie. Może być używana do rysowania
   wielokątów foremnych.

      >>> turtle.home()
      >>> turtle.position()
      (0.00,0.00)
      >>> turtle.heading()
      0.0
      >>> turtle.circle(50)
      >>> turtle.position()
      (-0.00,0.00)
      >>> turtle.heading()
      0.0
      >>> turtle.circle(120, 180)  # draw a semicircle
      >>> turtle.position()
      (0.00,240.00)
      >>> turtle.heading()
      180.0

turtle.dot(size=None, *color)

   Parametry:
      * **size** -- liczba całkowita >= 1 (jeśli podano)

      * **color** -- colorstring lub numeryczna krotka koloru

   Rysuje okrągłą kropkę o średnicy *size*, używając koloru *color*.
   Jeśli nie podano *size*, używana jest maksymalna wartość z
   pensize+4 i 2*pensize.

      >>> turtle.home()
      >>> turtle.dot()
      >>> turtle.fd(50); turtle.dot(20, "blue"); turtle.fd(50)
      >>> turtle.position()
      (100.00,-0.00)
      >>> turtle.heading()
      0.0

turtle.stamp()

   Stempluje kopię kształtu żółwia na płótnie w bieżącej pozycji
   żółwia. Zwraca stamp_id dla tego stempla, który może być użyty do
   usunięcia go przez wywołanie "clearstamp(stamp_id)".

      >>> turtle.color("blue")
      >>> turtle.stamp()
      11
      >>> turtle.fd(50)

turtle.clearstamp(stampid)

   Parametry:
      **stampid** -- liczba całkowita, musi być wartością zwróconą
      przez wywołanie poprzedniego "stamp()"

   Usunięcie stempla z podanym *stampid*.

      >>> turtle.position()
      (150.00,-0.00)
      >>> turtle.color("blue")
      >>> astamp = turtle.stamp()
      >>> turtle.fd(50)
      >>> turtle.position()
      (200.00,-0.00)
      >>> turtle.clearstamp(astamp)
      >>> turtle.position()
      (200.00,-0.00)

turtle.clearstamps(n=None)

   Parametry:
      **n** -- liczba całkowita (lub "None")

   Usuwa wszystkie lub pierwsze/ostatnie *n* stempli żółwia. Jeśli *n*
   to "None", usuwa wszystkie stemple, jeśli *n* > 0 usuwa pierwsze
   *n* stempli, inaczej jeśli *n* < 0 usuwa ostatnie *n* stempli.

      >>> for i in range(8):
      ...     turtle.stamp(); turtle.fd(30)
      13
      14
      15
      16
      17
      18
      19
      20
      >>> turtle.clearstamps(2)
      >>> turtle.clearstamps(-2)
      >>> turtle.clearstamps()

turtle.undo()

   Cofa (wielokrotnie) ostatnią akcję (akcje) żółwia. Liczba
   dostępnych cofnięć zależy od rozmiaru bufora cofania.

      >>> for i in range(4):
      ...     turtle.fd(50); turtle.lt(80)
      ...
      >>> for i in range(8):
      ...     turtle.undo()

turtle.speed(speed=None)

   Parametry:
      **speed** -- liczba całkowita w zakresie 0..10 lub nazwa
      prędkości (patrz poniżej)

   Ustawia prędkość żółwia na wartość liczby całkowitej w zakresie
   0..10. Jeśli nie podano argumentu, zwraca aktualną prędkość.

   Jeśli wartość wejściowa jest większa niż 10 lub mniejsza niż 0,5,
   prędkość jest ustawiana na 0. Nazwy prędkości są mapowane na
   wartości prędkości w następujący sposób:

   * "fastest":  0

   * "fast":  10

   * "normal":  6

   * "slow":  3

   * "slowest":  1

   Prędkości od 1 do 10 wymuszają coraz szybszą animację rysowania
   linii i obracania żółwia.

   Uwaga: *speed* = 0 oznacza, że *żadna* animacja nie ma miejsca.
   forward/back sprawia, że żółw skacze i podobnie left/right sprawia,
   że żółw natychmiast się obraca.

      >>> turtle.speed()
      3
      >>> turtle.speed('normal')
      >>> turtle.speed()
      6
      >>> turtle.speed(9)
      >>> turtle.speed()
      9


Pobieranie stanu żółwia
-----------------------

turtle.position()
turtle.pos()

   Zwraca bieżącą lokalizację żółwia (x,y) (jako wektor "Vec2D").

      >>> turtle.pos()
      (440.00,-0.00)

turtle.towards(x, y=None)

   Parametry:
      * **x** -- liczba lub para/wektor liczb lub instancja żółwia

      * **y** -- liczba, jeśli *x* jest liczbą, w przeciwnym razie
        "None"

   Zwraca kąt między linią od pozycji żółwia do pozycji określonej
   przez (x,y), wektor lub drugiego żółwia. Zależy to od orientacji
   początkowej żółwia, która zależy od trybu – „standard”/„world” lub
   „logo”.

      >>> turtle.goto(10, 10)
      >>> turtle.towards(0,0)
      225.0

turtle.xcor()

   Zwraca współrzędną x żółwia.

      >>> turtle.home()
      >>> turtle.left(50)
      >>> turtle.forward(100)
      >>> turtle.pos()
      (64.28,76.60)
      >>> print(round(turtle.xcor(), 5))
      64.27876

turtle.ycor()

   Zwraca współrzędną y żółwia.

      >>> turtle.home()
      >>> turtle.left(60)
      >>> turtle.forward(100)
      >>> print(turtle.pos())
      (50.00,86.60)
      >>> print(round(turtle.ycor(), 5))
      86.60254

turtle.heading()

   Zwraca aktualny kierunek żółwia (wartość zależy od trybu żółwia,
   patrz "mode()").

      >>> turtle.home()
      >>> turtle.left(67)
      >>> turtle.heading()
      67.0

turtle.distance(x, y=None)

   Parametry:
      * **x** -- liczba lub para/wektor liczb lub instancja żółwia

      * **y** -- liczba, jeśli *x* jest liczbą, w przeciwnym razie
        "None"

   Zwraca odległość od żółwia do (x,y), podanego wektora lub podanego
   innego żółwia, w jednostkach kroku żółwia.

      >>> turtle.home()
      >>> turtle.distance(30,40)
      50.0
      >>> turtle.distance((30,40))
      50.0
      >>> joe = Turtle()
      >>> joe.forward(77)
      >>> turtle.distance(joe)
      77.0


Ustawienia pomiarowe
--------------------

turtle.degrees(fullcircle=360.0)

   Parametry:
      **fullcircle** -- liczba

   Ustawia jednostki pomiaru kąta, tj. liczbę „stopni” dla pełnego
   okręgu. Domyślna wartość to 360 stopni.

      >>> turtle.home()
      >>> turtle.left(90)
      >>> turtle.heading()
      90.0

      Change angle measurement unit to grad (also known as gon,
      grade, or gradian and equals 1/100-th of the right angle.)
      >>> turtle.degrees(400.0)
      >>> turtle.heading()
      100.0
      >>> turtle.degrees(360)
      >>> turtle.heading()
      90.0

turtle.radians()

   Ustawia jednostki miary kąta na radiany. Odpowiednik
   "degrees(2*math.pi)".

      >>> turtle.home()
      >>> turtle.left(90)
      >>> turtle.heading()
      90.0
      >>> turtle.radians()
      >>> turtle.heading()
      1.5707963267948966


Kontrola pióra
--------------


Stan rysowania
~~~~~~~~~~~~~~

turtle.pendown()
turtle.pd()
turtle.down()

   Opuszcza pióro w dół – rysowanie podczas ruchu.

turtle.penup()
turtle.pu()
turtle.up()

   Podnosi pióro do góry – nierysowanie podczas ruchu.

turtle.pensize(width=None)
turtle.width(width=None)

   Parametry:
      **width** -- liczba dodatnia

   Ustawia grubość linii na *width* lub zwraca ją. Jeśli resizemode
   jest ustawiony na „auto”, a turtleshape jest wielokątem, wielokąt
   ten jest rysowany z taką samą grubością linii. Jeśli nie podano
   argumentu, zwracany jest bieżący rozmiar pióra.

      >>> turtle.pensize()
      1
      >>> turtle.pensize(10)   # from here on lines of width 10 are drawn

turtle.pen(pen=None, **pendict)

   Parametry:
      * **pen** -- słownik z niektórymi lub wszystkimi z poniższych
        kluczy

      * **pendict** -- jedno lub więcej argumentów nazwanych z
        poniższymi kluczami jako nazwami

   Zwraca lub ustawia atrybuty pióra w „pióro-słowniku” z
   następującymi parami klucz/wartość:

   * „shown”: True/False

   * „pendown”: True/False

   * „pencolor”: nazwa koloru (color-string) lub kolor-krotka

   * „fillcolor”: nazwa koloru (color-string) lub kolor-krotka

   * „pensize”: liczba dodatnia

   * „speed”: liczba z przedziału 0..10

   * „resizemode”: „auto” lub „user” lub „noresize”

   * „stretchfactor”: (liczba dodatnia, liczba dodatnia)

   * „outline”: liczba dodatnia

   * „tilt”: liczba

   Ten słownik może być użyty jako argument dla kolejnego wywołania
   "pen()" w celu przywrócenia poprzedniego stanu pióra. Co więcej,
   jeden lub więcej z tych atrybutów może być przekazany jako argument
   nazwany. Można to wykorzystać do ustawienia kilku atrybutów pióra w
   jednej instrukcji.

      >>> turtle.pen(fillcolor="black", pencolor="red", pensize=10)
      >>> sorted(turtle.pen().items())
      [('fillcolor', 'black'), ('outline', 1), ('pencolor', 'red'),
       ('pendown', True), ('pensize', 10), ('resizemode', 'noresize'),
       ('shearfactor', 0.0), ('shown', True), ('speed', 9),
       ('stretchfactor', (1.0, 1.0)), ('tilt', 0.0)]
      >>> penstate=turtle.pen()
      >>> turtle.color("yellow", "")
      >>> turtle.penup()
      >>> sorted(turtle.pen().items())[:3]
      [('fillcolor', ''), ('outline', 1), ('pencolor', 'yellow')]
      >>> turtle.pen(penstate, fillcolor="green")
      >>> sorted(turtle.pen().items())[:3]
      [('fillcolor', 'green'), ('outline', 1), ('pencolor', 'red')]

turtle.isdown()

   Zwraca "True" jeśli pióro jest opuszczone, "False" jeśli jest
   podniesione.

      >>> turtle.penup()
      >>> turtle.isdown()
      False
      >>> turtle.pendown()
      >>> turtle.isdown()
      True


Kontrola koloru
~~~~~~~~~~~~~~~

turtle.pencolor(*args)

   Zwraca lub ustawia kolor pióra.

   Dozwolone są cztery formaty wejściowe:

   "pencolor()"
      Zwraca bieżący kolor pióra jako ciąg specyfikacji koloru lub
      jako krotkę (patrz przykład). Może być użyty jako dane wejściowe
      do innego wywołania color/pencolor/fillcolor.

   "pencolor(colorstring)"
      Ustawia kolor pióra na *colorstring*, który jest ciągiem
      specyfikacji koloru Tk, takim jak ""red"", ""yellow"", lub
      ""#33cc8c"".

   "pencolor((r, g, b))"
      Ustawia kolor pióra na kolor RGB reprezentowany przez krotkę
      *r*, *g* i *b*. Każda z *r*, *g* i *b* musi należeć do zakresu
      0..colormode, gdzie colormode to 1.0 lub 255 (patrz
      "colormode()").

   "pencolor(r, g, b)"
      Ustawia kolor pióra na kolor RGB reprezentowany przez *r*, *g* i
      *b*.  Każda z *r*, *g* i *b* musi należeć do zakresu
      0..colormode.

   Jeśli turtleshape jest wielokątem, kontur tego wielokąta jest
   rysowany przy użyciu nowo ustawionego koloru pióra.

       >>> colormode()
       1.0
       >>> turtle.pencolor()
       'red'
       >>> turtle.pencolor("brown")
       >>> turtle.pencolor()
       'brown'
       >>> tup = (0.2, 0.8, 0.55)
       >>> turtle.pencolor(tup)
       >>> turtle.pencolor()
       (0.2, 0.8, 0.5490196078431373)
       >>> colormode(255)
       >>> turtle.pencolor()
       (51.0, 204.0, 140.0)
       >>> turtle.pencolor('#32c18f')
       >>> turtle.pencolor()
       (50.0, 193.0, 143.0)

turtle.fillcolor(*args)

   Zwraca lub ustawia kolor wypełnienia.

   Dozwolone są cztery formaty wejściowe:

   "fillcolor()"
      Zwraca bieżący kolor wypełnienia jako ciąg specyfikacji koloru,
      ewentualnie w formacie krotki (patrz przykład). Może być użyty
      jako dane wejściowe do innego wywołania
      color/pencolor/fillcolor.

   "fillcolor(colorstring)"
      Ustawia kolor wypełnienia na *colorstring*, który jest ciągiem
      specyfikacji koloru Tk, takim jak ""red"", ""yellow"", lub
      ""#33cc8c"".

   "fillcolor((r, g, b))"
      Ustawia kolor wypełnienia na kolor RGB reprezentowany przez
      krotkę *r*, *g* i *b*.  Każdy z *r*, *g* i *b* musi należeć do
      zakresu 0..colormode, gdzie colormode to 1.0 lub 255 (patrz
      "colormode()").

   "fillcolor(r, g, b)"
      Ustawia kolor wypełnienia na kolor RGB reprezentowany przez *r*,
      *g* i *b*.  Każde z *r*, *g* i *b* musi należeć do zakresu
      0..colormode.

   Jeśli turtleshape jest wielokątem, wnętrze tego wielokąta jest
   rysowane z nowo ustawionym kolorem wypełnienia.

       >>> turtle.fillcolor("violet")
       >>> turtle.fillcolor()
       'violet'
       >>> turtle.pencolor()
       (50.0, 193.0, 143.0)
       >>> turtle.fillcolor((50, 193, 143))  # Integers, not floats
       >>> turtle.fillcolor()
       (50.0, 193.0, 143.0)
       >>> turtle.fillcolor('#ffffff')
       >>> turtle.fillcolor()
       (255.0, 255.0, 255.0)

turtle.color(*args)

   Zwraca lub ustawia kolor pióra i wypełnienia.

   Dozwolonych jest kilka formatów wejściowych. Używają one od 0 do 3
   argumentów w następujący sposób:

   "color()"
      Zwraca bieżący kolor pióra i bieżący kolor wypełnienia jako parę
      ciągów specyfikacji kolorów lub krotek zwracanych przez
      "pencolor()" i "fillcolor()".

   "color(colorstring)", "color((r,g,b))", "color(r,g,b)"
      Dane wejściowe jak w "pencolor()", ustawiają zarówno kolor
      wypełnienia, jak i kolor pióra na podaną wartość.

   "color(colorstring1, colorstring2)", "color((r1,g1,b1),
   (r2,g2,b2))"
      Odpowiednik dla "pencolor(colorstring1)" i
      "fillcolor(colorstring2)" oraz analogicznie, jeśli używany jest
      inny format wejścia.

   Jeśli turtleshape jest wielokątem, kontur i wnętrze tego wielokąta
   są rysowane z nowo ustawionymi kolorami.

       >>> turtle.color("red", "green")
       >>> turtle.color()
       ('red', 'green')
       >>> color("#285078", "#a0c8f0")
       >>> color()
       ((40.0, 80.0, 120.0), (160.0, 200.0, 240.0))

Zobacz także: Metoda klasy Screen "colormode()".


Wypełnienie
~~~~~~~~~~~

turtle.filling()

   Zwraca fillstate ("True" jeśli wypełnienie, "False" w przeciwnym
   razie).

       >>> turtle.begin_fill()
       >>> if turtle.filling():
       ...    turtle.pensize(5)
       ... else:
       ...    turtle.pensize(3)

turtle.begin_fill()

   Do wywołania tuż przed rysowaniem kształtu do wypełnienia.

turtle.end_fill()

   Wypełnia kształt narysowany po ostatnim wywołaniu "begin_fill()".

   To, czy obszary nakładania się przecinających się wielokątów lub
   wielu kształtów są wypełnione, zależy od grafiki systemu
   operacyjnego, typu nakładania się i liczby nakładających się
   obszarów.  Na przykład żółwiowa gwiazda na górze rozdziału może być
   cała żółta lub mieć kilka białych obszarów.

      >>> turtle.color("black", "red")
      >>> turtle.begin_fill()
      >>> turtle.circle(80)
      >>> turtle.end_fill()


Więcej kontroli rysowania
~~~~~~~~~~~~~~~~~~~~~~~~~

turtle.reset()

   Usuń rysunki żółwia z ekranu, ponownie wyśrodkuj żółwia i ustaw
   zmienne na wartości domyślne.

      >>> turtle.goto(0,-22)
      >>> turtle.left(100)
      >>> turtle.position()
      (0.00,-22.00)
      >>> turtle.heading()
      100.0
      >>> turtle.reset()
      >>> turtle.position()
      (0.00,0.00)
      >>> turtle.heading()
      0.0

turtle.clear()

   Usuwa rysunki żółwia z ekranu. Nie rusza żółwia. Stan i pozycja
   żółwia, a także rysunki innych żółwi, nie zostaną zmienione.

turtle.write(arg, move=False, align='left', font=('Arial', 8, 'normal'))

   Parametry:
      * **arg** -- obiekt, który ma zostać zapisany na TurtleScreen

      * **move** -- True/False

      * **align** -- jedna z wartości „left”, „center” lub „right”

      * **font** -- trójka wartości (fontname, fontsize, fonttype)

   Pisze tekst – reprezentację obiektu *arg* – w bieżącej pozycji
   żółwia zgodnie z *align* ("left", "center" lub "right") i z podaną
   czcionką.  Jeśli *move* to "True", pióro jest przesuwane do prawego
   dolnego rogu tekstu.  Domyślnie *move* ma wartość "False".

   >>> turtle.write("Home = ", True, align="center")
   >>> turtle.write((0,0), True)


Stan żółwia
-----------


Widoczność
~~~~~~~~~~

turtle.hideturtle()
turtle.ht()

   Czyni żółwia niewidocznym. Dobrym pomysłem jest zrobienie tego w
   trakcie wykonywania złożonego rysunku, ponieważ ukrycie żółwia
   znacznie przyspiesza rysowanie.

      >>> turtle.hideturtle()

turtle.showturtle()
turtle.st()

   Sprawia, że żółw jest widoczny.

      >>> turtle.showturtle()

turtle.isvisible()

   Zwraca "True" jeśli żółw jest widoczny, "False" jeśli jest ukryty.

   >>> turtle.hideturtle()
   >>> turtle.isvisible()
   False
   >>> turtle.showturtle()
   >>> turtle.isvisible()
   True


Wygląd
~~~~~~

turtle.shape(name=None)

   Parametry:
      **name** -- ciąg znaków, który jest prawidłową nazwą kształtu

   Ustawia kształt żółwia na kształt o podanej nazwie *name* lub,
   jeśli nazwa nie została podana, zwraca nazwę bieżącego kształtu.
   Kształt o nazwie *name* musi istnieć w słowniku kształtów
   TurtleScreen. Początkowo dostępne są następujące kształty
   wielokątów: "arrow", "turtle", "circle", "square", "triangle",
   "classic". Aby dowiedzieć się, jak radzić sobie z kształtami,
   zobacz metodę Screen "register_shape()".

      >>> turtle.shape()
      'classic'
      >>> turtle.shape("turtle")
      >>> turtle.shape()
      'turtle'

turtle.resizemode(rmode=None)

   Parametry:
      **rmode** -- jeden z ciągów znaków „auto”, „user”, „noresize”

   Ustawia tryb zmiany rozmiaru na jedną z wartości: „auto”, „user”,
   „noresize”. Jeśli nie podano *rmode*, zwraca bieżący tryb zmiany
   rozmiaru. Różne tryby zmiany rozmiaru mają następujące skutki:

   * "auto": dostosowuje wygląd żółwia do wartości rozmiaru pióra.

   * "user": dostosowuje wygląd żółwia zgodnie z wartościami
     stretchfactor i outlinewidth (outline), które są ustawiane przez
     "shapesize()".

   * "noresize": nie następuje adaptacja wyglądu żółwia.

   "resizemode("user")" jest wywoływana przez "shapesize()", gdy jest
   użyte z argumentami.

      >>> turtle.resizemode()
      'noresize'
      >>> turtle.resizemode("auto")
      >>> turtle.resizemode()
      'auto'

turtle.shapesize(stretch_wid=None, stretch_len=None, outline=None)
turtle.turtlesize(stretch_wid=None, stretch_len=None, outline=None)

   Parametry:
      * **stretch_wid** -- liczba dodatnia

      * **stretch_len** -- liczba dodatnia

      * **outline** -- liczba dodatnia

   Return or set the pen's attributes x/y-stretchfactors and/or
   outline.  Set resizemode to "user".  If and only if resizemode is
   set to "user", the turtle will be displayed stretched according to
   its stretchfactors: *stretch_wid* is stretchfactor perpendicular to
   its orientation, *stretch_len* is stretchfactor in direction of its
   orientation, *outline* determines the width of the shape's outline.

      >>> turtle.shapesize()
      (1.0, 1.0, 1)
      >>> turtle.resizemode("user")
      >>> turtle.shapesize(5, 5, 12)
      >>> turtle.shapesize()
      (5, 5, 12)
      >>> turtle.shapesize(outline=8)
      >>> turtle.shapesize()
      (5, 5, 8)

turtle.shearfactor(shear=None)

   Parametry:
      **shear** -- number (optional)

   Set or return the current shearfactor. Shear the turtleshape
   according to the given shearfactor shear, which is the tangent of
   the shear angle. Do *not* change the turtle's heading (direction of
   movement). If shear is not given: return the current shearfactor,
   i. e. the tangent of the shear angle, by which lines parallel to
   the heading of the turtle are sheared.

       >>> turtle.shape("circle")
       >>> turtle.shapesize(5,2)
       >>> turtle.shearfactor(0.5)
       >>> turtle.shearfactor()
       0.5

turtle.tilt(angle)

   Parametry:
      **angle** -- liczba

   Rotate the turtleshape by *angle* from its current tilt-angle, but
   do *not* change the turtle's heading (direction of movement).

      >>> turtle.reset()
      >>> turtle.shape("circle")
      >>> turtle.shapesize(5,2)
      >>> turtle.tilt(30)
      >>> turtle.fd(50)
      >>> turtle.tilt(30)
      >>> turtle.fd(50)

turtle.settiltangle(angle)

   Parametry:
      **angle** -- liczba

   Rotate the turtleshape to point in the direction specified by
   *angle*, regardless of its current tilt-angle.  *Do not* change the
   turtle's heading (direction of movement).

      >>> turtle.reset()
      >>> turtle.shape("circle")
      >>> turtle.shapesize(5,2)
      >>> turtle.settiltangle(45)
      >>> turtle.fd(50)
      >>> turtle.settiltangle(-45)
      >>> turtle.fd(50)

   Niezalecane od wersji 3.1.

turtle.tiltangle(angle=None)

   Parametry:
      **angle** -- a number (optional)

   Set or return the current tilt-angle. If angle is given, rotate the
   turtleshape to point in the direction specified by angle,
   regardless of its current tilt-angle. Do *not* change the turtle's
   heading (direction of movement). If angle is not given: return the
   current tilt-angle, i. e. the angle between the orientation of the
   turtleshape and the heading of the turtle (its direction of
   movement).

      >>> turtle.reset()
      >>> turtle.shape("circle")
      >>> turtle.shapesize(5,2)
      >>> turtle.tilt(45)
      >>> turtle.tiltangle()
      45.0

turtle.shapetransform(t11=None, t12=None, t21=None, t22=None)

   Parametry:
      * **t11** -- a number (optional)

      * **t12** -- a number (optional)

      * **t21** -- a number (optional)

      * **t12** -- a number (optional)

   Set or return the current transformation matrix of the turtle
   shape.

   If none of the matrix elements are given, return the transformation
   matrix as a tuple of 4 elements. Otherwise set the given elements
   and transform the turtleshape according to the matrix consisting of
   first row t11, t12 and second row t21, t22. The determinant t11 *
   t22 - t12 * t21 must not be zero, otherwise an error is raised.
   Modify stretchfactor, shearfactor and tiltangle according to the
   given matrix.

      >>> turtle = Turtle()
      >>> turtle.shape("square")
      >>> turtle.shapesize(4,2)
      >>> turtle.shearfactor(-0.5)
      >>> turtle.shapetransform()
      (4.0, -1.0, -0.0, 2.0)

turtle.get_shapepoly()

   Return the current shape polygon as tuple of coordinate pairs. This
   can be used to define a new shape or components of a compound
   shape.

      >>> turtle.shape("square")
      >>> turtle.shapetransform(4, -1, 0, 2)
      >>> turtle.get_shapepoly()
      ((50, -20), (30, 20), (-50, 20), (-30, -20))


Korzystanie ze zdarzeń
----------------------

turtle.onclick(fun, btn=1, add=None)

   Parametry:
      * **fun** -- a function with two arguments which will be called
        with the coordinates of the clicked point on the canvas

      * **btn** -- number of the mouse-button, defaults to 1 (left
        mouse button)

      * **add** -- "True" or "False" -- if "True", a new binding will
        be added, otherwise it will replace a former binding

   Bind *fun* to mouse-click events on this turtle.  If *fun* is
   "None", existing bindings are removed.  Example for the anonymous
   turtle, i.e. the procedural way:

      >>> def turn(x, y):
      ...     left(180)
      ...
      >>> onclick(turn)  # Now clicking into the turtle will turn it.
      >>> onclick(None)  # event-binding will be removed

turtle.onrelease(fun, btn=1, add=None)

   Parametry:
      * **fun** -- a function with two arguments which will be called
        with the coordinates of the clicked point on the canvas

      * **btn** -- number of the mouse-button, defaults to 1 (left
        mouse button)

      * **add** -- "True" or "False" -- if "True", a new binding will
        be added, otherwise it will replace a former binding

   Bind *fun* to mouse-button-release events on this turtle.  If *fun*
   is "None", existing bindings are removed.

      >>> class MyTurtle(Turtle):
      ...     def glow(self,x,y):
      ...         self.fillcolor("red")
      ...     def unglow(self,x,y):
      ...         self.fillcolor("")
      ...
      >>> turtle = MyTurtle()
      >>> turtle.onclick(turtle.glow)     # clicking on turtle turns fillcolor red,
      >>> turtle.onrelease(turtle.unglow) # releasing turns it to transparent.

turtle.ondrag(fun, btn=1, add=None)

   Parametry:
      * **fun** -- a function with two arguments which will be called
        with the coordinates of the clicked point on the canvas

      * **btn** -- number of the mouse-button, defaults to 1 (left
        mouse button)

      * **add** -- "True" or "False" -- if "True", a new binding will
        be added, otherwise it will replace a former binding

   Bind *fun* to mouse-move events on this turtle.  If *fun* is
   "None", existing bindings are removed.

   Remark: Every sequence of mouse-move-events on a turtle is preceded
   by a mouse-click event on that turtle.

      >>> turtle.ondrag(turtle.goto)

   Subsequently, clicking and dragging the Turtle will move it across
   the screen thereby producing handdrawings (if pen is down).


Specjalne metody żółwi
----------------------

turtle.begin_poly()

   Start recording the vertices of a polygon.  Current turtle position
   is first vertex of polygon.

turtle.end_poly()

   Stop recording the vertices of a polygon.  Current turtle position
   is last vertex of polygon.  This will be connected with the first
   vertex.

turtle.get_poly()

   Return the last recorded polygon.

      >>> turtle.home()
      >>> turtle.begin_poly()
      >>> turtle.fd(100)
      >>> turtle.left(20)
      >>> turtle.fd(30)
      >>> turtle.left(60)
      >>> turtle.fd(50)
      >>> turtle.end_poly()
      >>> p = turtle.get_poly()
      >>> register_shape("myFavouriteShape", p)

turtle.clone()

   Create and return a clone of the turtle with same position, heading
   and turtle properties.

      >>> mick = Turtle()
      >>> joe = mick.clone()

turtle.getturtle()
turtle.getpen()

   Return the Turtle object itself.  Only reasonable use: as a
   function to return the "anonymous turtle":

      >>> pet = getturtle()
      >>> pet.fd(50)
      >>> pet
      <turtle.Turtle object at 0x...>

turtle.getscreen()

   Return the "TurtleScreen" object the turtle is drawing on.
   TurtleScreen methods can then be called for that object.

      >>> ts = turtle.getscreen()
      >>> ts
      <turtle._Screen object at 0x...>
      >>> ts.bgcolor("pink")

turtle.setundobuffer(size)

   Parametry:
      **size** -- an integer or "None"

   Set or disable undobuffer.  If *size* is an integer, an empty
   undobuffer of given size is installed.  *size* gives the maximum
   number of turtle actions that can be undone by the "undo()"
   method/function.  If *size* is "None", the undobuffer is disabled.

      >>> turtle.setundobuffer(42)

turtle.undobufferentries()

   Return number of entries in the undobuffer.

      >>> while undobufferentries():
      ...     undo()


Compound shapes
---------------

To use compound turtle shapes, which consist of several polygons of
different color, you must use the helper class "Shape" explicitly as
described below:

1. Create an empty Shape object of type "compound".

2. Add as many components to this object as desired, using the
   "addcomponent()" method.

   Na przykład:

      >>> s = Shape("compound")
      >>> poly1 = ((0,0),(10,-5),(0,10),(-10,-5))
      >>> s.addcomponent(poly1, "red", "blue")
      >>> poly2 = ((0,0),(10,-5),(-10,-5))
      >>> s.addcomponent(poly2, "blue", "red")

3. Now add the Shape to the Screen's shapelist and use it:

      >>> register_shape("myshape", s)
      >>> shape("myshape")

Informacja:

  The "Shape" class is used internally by the "register_shape()"
  method in different ways.  The application programmer has to deal
  with the Shape class *only* when using compound shapes like shown
  above!


Methods of TurtleScreen/Screen and corresponding functions
==========================================================

Most of the examples in this section refer to a TurtleScreen instance
called "screen".


Kontrola okna
-------------

turtle.bgcolor(*args)

   Parametry:
      **args** -- a color string or three numbers in the range
      0..colormode or a 3-tuple of such numbers

   Set or return background color of the TurtleScreen.

      >>> screen.bgcolor("orange")
      >>> screen.bgcolor()
      'orange'
      >>> screen.bgcolor("#800080")
      >>> screen.bgcolor()
      (128.0, 0.0, 128.0)

turtle.bgpic(picname=None)

   Parametry:
      **picname** -- a string, name of a gif-file or ""nopic"", or
      "None"

   Set background image or return name of current backgroundimage.  If
   *picname* is a filename, set the corresponding image as background.
   If *picname* is ""nopic"", delete background image, if present.  If
   *picname* is "None", return the filename of the current
   backgroundimage.

      >>> screen.bgpic()
      'nopic'
      >>> screen.bgpic("landscape.gif")
      >>> screen.bgpic()
      "landscape.gif"

turtle.clear()

   Informacja:

     This TurtleScreen method is available as a global function only
     under the name "clearscreen".  The global function "clear" is a
     different one derived from the Turtle method "clear".

turtle.clearscreen()

   Delete all drawings and all turtles from the TurtleScreen.  Reset
   the now empty TurtleScreen to its initial state: white background,
   no background image, no event bindings and tracing on.

turtle.reset()

   Informacja:

     This TurtleScreen method is available as a global function only
     under the name "resetscreen".  The global function "reset" is
     another one derived from the Turtle method "reset".

turtle.resetscreen()

   Reset all Turtles on the Screen to their initial state.

turtle.screensize(canvwidth=None, canvheight=None, bg=None)

   Parametry:
      * **canvwidth** -- positive integer, new width of canvas in
        pixels

      * **canvheight** -- positive integer, new height of canvas in
        pixels

      * **bg** -- colorstring or color-tuple, new background color

   If no arguments are given, return current (canvaswidth,
   canvasheight).  Else resize the canvas the turtles are drawing on.
   Do not alter the drawing window.  To observe hidden parts of the
   canvas, use the scrollbars. With this method, one can make visible
   those parts of a drawing which were outside the canvas before.

   >>> screen.screensize()
   (400, 300)
   >>> screen.screensize(2000,1500)
   >>> screen.screensize()
   (2000, 1500)

   e.g. to search for an erroneously escaped turtle ;-)

turtle.setworldcoordinates(llx, lly, urx, ury)

   Parametry:
      * **llx** -- a number, x-coordinate of lower left corner of
        canvas

      * **lly** -- a number, y-coordinate of lower left corner of
        canvas

      * **urx** -- a number, x-coordinate of upper right corner of
        canvas

      * **ury** -- a number, y-coordinate of upper right corner of
        canvas

   Set up user-defined coordinate system and switch to mode "world" if
   necessary.  This performs a "screen.reset()".  If mode "world" is
   already active, all drawings are redrawn according to the new
   coordinates.

   **ATTENTION**: in user-defined coordinate systems angles may appear
   distorted.

      >>> screen.reset()
      >>> screen.setworldcoordinates(-50,-7.5,50,7.5)
      >>> for _ in range(72):
      ...     left(10)
      ...
      >>> for _ in range(8):
      ...     left(45); fd(2)   # a regular octagon


Kontrola animacji
-----------------

turtle.delay(delay=None)

   Parametry:
      **delay** -- positive integer

   Set or return the drawing *delay* in milliseconds.  (This is
   approximately the time interval between two consecutive canvas
   updates.)  The longer the drawing delay, the slower the animation.

   Optional argument:

      >>> screen.delay()
      10
      >>> screen.delay(5)
      >>> screen.delay()
      5

turtle.tracer(n=None, delay=None)

   Parametry:
      * **n** -- nonnegative integer

      * **delay** -- nonnegative integer

   Turn turtle animation on/off and set delay for update drawings.  If
   *n* is given, only each n-th regular screen update is really
   performed.  (Can be used to accelerate the drawing of complex
   graphics.)  When called without arguments, returns the currently
   stored value of n. Second argument sets delay value (see
   "delay()").

      >>> screen.tracer(8, 25)
      >>> dist = 2
      >>> for i in range(200):
      ...     fd(dist)
      ...     rt(90)
      ...     dist += 2

turtle.update()

   Perform a TurtleScreen update. To be used when tracer is turned
   off.

See also the RawTurtle/Turtle method "speed()".


Korzystanie ze zdarzeń ekranowych
---------------------------------

turtle.listen(xdummy=None, ydummy=None)

   Set focus on TurtleScreen (in order to collect key-events).  Dummy
   arguments are provided in order to be able to pass "listen()" to
   the onclick method.

turtle.onkey(fun, key)
turtle.onkeyrelease(fun, key)

   Parametry:
      * **fun** -- a function with no arguments or "None"

      * **key** -- a string: key (e.g. "a") or key-symbol (e.g.
        "space")

   Bind *fun* to key-release event of key.  If *fun* is "None", event
   bindings are removed. Remark: in order to be able to register key-
   events, TurtleScreen must have the focus. (See method "listen()".)

      >>> def f():
      ...     fd(50)
      ...     lt(60)
      ...
      >>> screen.onkey(f, "Up")
      >>> screen.listen()

turtle.onkeypress(fun, key=None)

   Parametry:
      * **fun** -- a function with no arguments or "None"

      * **key** -- a string: key (e.g. "a") or key-symbol (e.g.
        "space")

   Bind *fun* to key-press event of key if key is given, or to any
   key-press-event if no key is given. Remark: in order to be able to
   register key-events, TurtleScreen must have focus. (See method
   "listen()".)

      >>> def f():
      ...     fd(50)
      ...
      >>> screen.onkey(f, "Up")
      >>> screen.listen()

turtle.onclick(fun, btn=1, add=None)
turtle.onscreenclick(fun, btn=1, add=None)

   Parametry:
      * **fun** -- a function with two arguments which will be called
        with the coordinates of the clicked point on the canvas

      * **btn** -- number of the mouse-button, defaults to 1 (left
        mouse button)

      * **add** -- "True" or "False" -- if "True", a new binding will
        be added, otherwise it will replace a former binding

   Bind *fun* to mouse-click events on this screen.  If *fun* is
   "None", existing bindings are removed.

   Example for a TurtleScreen instance named "screen" and a Turtle
   instance named "turtle":

      >>> screen.onclick(turtle.goto) # Subsequently clicking into the TurtleScreen will
      >>>                             # make the turtle move to the clicked point.
      >>> screen.onclick(None)        # remove event binding again

   Informacja:

     This TurtleScreen method is available as a global function only
     under the name "onscreenclick".  The global function "onclick" is
     another one derived from the Turtle method "onclick".

turtle.ontimer(fun, t=0)

   Parametry:
      * **fun** -- a function with no arguments

      * **t** -- a number >= 0

   Install a timer that calls *fun* after *t* milliseconds.

      >>> running = True
      >>> def f():
      ...     if running:
      ...         fd(50)
      ...         lt(60)
      ...         screen.ontimer(f, 250)
      >>> f()   ### makes the turtle march around
      >>> running = False

turtle.mainloop()
turtle.done()

   Starts event loop - calling Tkinter's mainloop function. Must be
   the last statement in a turtle graphics program. Must *not* be used
   if a script is run from within IDLE in -n mode (No subprocess) -
   for interactive use of turtle graphics.

      >>> screen.mainloop()


Metody wprowadzania danych
--------------------------

turtle.textinput(title, prompt)

   Parametry:
      * **title** -- ciąg znaków

      * **prompt** -- ciąg znaków

   Pop up a dialog window for input of a string. Parameter title is
   the title of the dialog window, prompt is a text mostly describing
   what information to input. Return the string input. If the dialog
   is canceled, return "None".

      >>> screen.textinput("NIM", "Name of first player:")

turtle.numinput(title, prompt, default=None, minval=None, maxval=None)

   Parametry:
      * **title** -- ciąg znaków

      * **prompt** -- ciąg znaków

      * **default** -- number (optional)

      * **minval** -- number (optional)

      * **maxval** -- number (optional)

   Pop up a dialog window for input of a number. title is the title of
   the dialog window, prompt is a text mostly describing what
   numerical information to input. default: default value, minval:
   minimum value for input, maxval: maximum value for input The number
   input must be in the range minval .. maxval if these are given. If
   not, a hint is issued and the dialog remains open for correction.
   Return the number input. If the dialog is canceled,  return "None".

      >>> screen.numinput("Poker", "Your stakes:", 1000, minval=10, maxval=10000)


Ustawienia i metody specjalne
-----------------------------

turtle.mode(mode=None)

   Parametry:
      **mode** -- one of the strings "standard", "logo" or "world"

   Set turtle mode ("standard", "logo" or "world") and perform reset.
   If mode is not given, current mode is returned.

   Mode "standard" is compatible with old "turtle".  Mode "logo" is
   compatible with most Logo turtle graphics.  Mode "world" uses user-
   defined "world coordinates". **Attention**: in this mode angles
   appear distorted if "x/y" unit-ratio doesn't equal 1.

   +--------------+---------------------------+---------------------+
   | Mode         | Initial turtle heading    | positive angles     |
   |==============|===========================|=====================|
   | "standard"   | to the right (east)       | counterclockwise    |
   +--------------+---------------------------+---------------------+
   | "logo"       | upward    (north)         | clockwise           |
   +--------------+---------------------------+---------------------+

      >>> mode("logo")   # resets turtle heading to north
      >>> mode()
      'logo'

turtle.colormode(cmode=None)

   Parametry:
      **cmode** -- one of the values 1.0 or 255

   Return the colormode or set it to 1.0 or 255.  Subsequently *r*,
   *g*, *b* values of color triples have to be in the range
   0..*cmode*.

      >>> screen.colormode(1)
      >>> turtle.pencolor(240, 160, 80)
      Traceback (most recent call last):
           ...
      TurtleGraphicsError: bad color sequence: (240, 160, 80)
      >>> screen.colormode()
      1.0
      >>> screen.colormode(255)
      >>> screen.colormode()
      255
      >>> turtle.pencolor(240,160,80)

turtle.getcanvas()

   Return the Canvas of this TurtleScreen.  Useful for insiders who
   know what to do with a Tkinter Canvas.

      >>> cv = screen.getcanvas()
      >>> cv
      <turtle.ScrolledCanvas object ...>

turtle.getshapes()

   Return a list of names of all currently available turtle shapes.

      >>> screen.getshapes()
      ['arrow', 'blank', 'circle', ..., 'turtle']

turtle.register_shape(name, shape=None)
turtle.addshape(name, shape=None)

   There are three different ways to call this function:

   1. *name* is the name of a gif-file and *shape* is "None": Install
      the corresponding image shape.

         >>> screen.register_shape("turtle.gif")

      Informacja:

        Image shapes *do not* rotate when turning the turtle, so they
        do not display the heading of the turtle!

   2. *name* is an arbitrary string and *shape* is a tuple of pairs of
      coordinates: Install the corresponding polygon shape.

         >>> screen.register_shape("triangle", ((5,-3), (0,5), (-5,-3)))

   3. *name* is an arbitrary string and shape is a (compound) "Shape"
      object: Install the corresponding compound shape.

   Add a turtle shape to TurtleScreen's shapelist.  Only thusly
   registered shapes can be used by issuing the command
   "shape(shapename)".

turtle.turtles()

   Return the list of turtles on the screen.

      >>> for turtle in screen.turtles():
      ...     turtle.color("red")

turtle.window_height()

   Return the height of the turtle window.

      >>> screen.window_height()
      480

turtle.window_width()

   Return the width of the turtle window.

      >>> screen.window_width()
      640


Methods specific to Screen, not inherited from TurtleScreen
-----------------------------------------------------------

turtle.bye()

   Shut the turtlegraphics window.

turtle.exitonclick()

   Bind "bye()" method to mouse clicks on the Screen.

   If the value "using_IDLE" in the configuration dictionary is
   "False" (default value), also enter mainloop.  Remark: If IDLE with
   the "-n" switch (no subprocess) is used, this value should be set
   to "True" in "turtle.cfg".  In this case IDLE's own mainloop is
   active also for the client script.

turtle.setup(width=_CFG['width'], height=_CFG['height'], startx=_CFG['leftright'], starty=_CFG['topbottom'])

   Set the size and position of the main window.  Default values of
   arguments are stored in the configuration dictionary and can be
   changed via a "turtle.cfg" file.

   Parametry:
      * **width** -- if an integer, a size in pixels, if a float, a
        fraction of the screen; default is 50% of screen

      * **height** -- if an integer, the height in pixels, if a float,
        a fraction of the screen; default is 75% of screen

      * **startx** -- if positive, starting position in pixels from
        the left edge of the screen, if negative from the right edge,
        if "None", center window horizontally

      * **starty** -- if positive, starting position in pixels from
        the top edge of the screen, if negative from the bottom edge,
        if "None", center window vertically

      >>> screen.setup (width=200, height=200, startx=0, starty=0)
      >>>              # sets window to 200x200 pixels, in upper left of screen
      >>> screen.setup(width=.75, height=0.5, startx=None, starty=None)
      >>>              # sets window to 75% of screen by 50% of screen and centers

turtle.title(titlestring)

   Parametry:
      **titlestring** -- a string that is shown in the titlebar of the
      turtle graphics window

   Set title of turtle window to *titlestring*.

      >>> screen.title("Welcome to the turtle zoo!")


Public classes
==============

class turtle.RawTurtle(canvas)
class turtle.RawPen(canvas)

   Parametry:
      **canvas** -- a "tkinter.Canvas", a "ScrolledCanvas" or a
      "TurtleScreen"

   Create a turtle.  The turtle has all methods described above as
   "methods of Turtle/RawTurtle".

class turtle.Turtle

   Subclass of RawTurtle, has the same interface but draws on a
   default "Screen" object created automatically when needed for the
   first time.

class turtle.TurtleScreen(cv)

   Parametry:
      **cv** -- a "tkinter.Canvas"

   Provides screen oriented methods like "bgcolor()" etc. that are
   described above.

class turtle.Screen

   Subclass of TurtleScreen, with four methods added.

class turtle.ScrolledCanvas(master)

   Parametry:
      **master** -- some Tkinter widget to contain the ScrolledCanvas,
      i.e. a Tkinter-canvas with scrollbars added

   Used by class Screen, which thus automatically provides a
   ScrolledCanvas as playground for the turtles.

class turtle.Shape(type_, data)

   Parametry:
      **type_** -- one of the strings "polygon", "image", "compound"

   Data structure modeling shapes.  The pair "(type_, data)" must
   follow this specification:

   +-------------+------------------------------------------------------------+
   | *type_*     | *data*                                                     |
   |=============|============================================================|
   | "polygon"   | a polygon-tuple, i.e. a tuple of pairs of coordinates      |
   +-------------+------------------------------------------------------------+
   | "image"     | an image  (in this form only used internally!)             |
   +-------------+------------------------------------------------------------+
   | "compound"  | "None" (a compound shape has to be constructed using the   |
   |             | "addcomponent()" method)                                   |
   +-------------+------------------------------------------------------------+

   addcomponent(poly, fill, outline=None)

      Parametry:
         * **poly** -- a polygon, i.e. a tuple of pairs of numbers

         * **fill** -- a color the *poly* will be filled with

         * **outline** -- a color for the poly's outline (if given)

      Przykład:

         >>> poly = ((0,0),(10,-5),(0,10),(-10,-5))
         >>> s = Shape("compound")
         >>> s.addcomponent(poly, "red", "blue")
         >>> # ... add more components and then use register_shape()

      See Compound shapes.

class turtle.Vec2D(x, y)

   A two-dimensional vector class, used as a helper class for
   implementing turtle graphics.  May be useful for turtle graphics
   programs too.  Derived from tuple, so a vector is a tuple!

   Provides (for *a*, *b* vectors, *k* number):

   * "a + b" vector addition

   * "a - b" vector subtraction

   * "a * b" inner product

   * "k * a" and "a * k" multiplication with scalar

   * "abs(a)" absolute value of a

   * "a.rotate(angle)" rotation


Help and configuration
======================


How to use help
---------------

The public methods of the Screen and Turtle classes are documented
extensively via docstrings.  So these can be used as online-help via
the Python help facilities:

* When using IDLE, tooltips show the signatures and first lines of the
  docstrings of typed in function-/method calls.

* Calling "help()" on methods or functions displays the docstrings:

     >>> help(Screen.bgcolor)
     Help on method bgcolor in module turtle:

     bgcolor(self, *args) unbound turtle.Screen method
         Set or return backgroundcolor of the TurtleScreen.

         Arguments (if given): a color string or three numbers
         in the range 0..colormode or a 3-tuple of such numbers.


           >>> screen.bgcolor("orange")
           >>> screen.bgcolor()
           "orange"
           >>> screen.bgcolor(0.5,0,0.5)
           >>> screen.bgcolor()
           "#800080"

     >>> help(Turtle.penup)
     Help on method penup in module turtle:

     penup(self) unbound turtle.Turtle method
         Pull the pen up -- no drawing when moving.

         Aliases: penup | pu | up

         No argument

         >>> turtle.penup()

* The docstrings of the functions which are derived from methods have
  a modified form:

     >>> help(bgcolor)
     Help on function bgcolor in module turtle:

     bgcolor(*args)
         Set or return backgroundcolor of the TurtleScreen.

         Arguments (if given): a color string or three numbers
         in the range 0..colormode or a 3-tuple of such numbers.

         Example::

           >>> bgcolor("orange")
           >>> bgcolor()
           "orange"
           >>> bgcolor(0.5,0,0.5)
           >>> bgcolor()
           "#800080"

     >>> help(penup)
     Help on function penup in module turtle:

     penup()
         Pull the pen up -- no drawing when moving.

         Aliases: penup | pu | up

         No argument

         Example:
         >>> penup()

These modified docstrings are created automatically together with the
function definitions that are derived from the methods at import time.


Translation of docstrings into different languages
--------------------------------------------------

There is a utility to create a dictionary the keys of which are the
method names and the values of which are the docstrings of the public
methods of the classes Screen and Turtle.

turtle.write_docstringdict(filename='turtle_docstringdict')

   Parametry:
      **filename** -- a string, used as filename

   Create and write docstring-dictionary to a Python script with the
   given filename.  This function has to be called explicitly (it is
   not used by the turtle graphics classes).  The docstring dictionary
   will be written to the Python script "*filename*.py".  It is
   intended to serve as a template for translation of the docstrings
   into different languages.

If you (or your students) want to use "turtle" with online help in
your native language, you have to translate the docstrings and save
the resulting file as e.g. "turtle_docstringdict_german.py".

If you have an appropriate entry in your "turtle.cfg" file this
dictionary will be read in at import time and will replace the
original English docstrings.

At the time of this writing there are docstring dictionaries in German
and in Italian.  (Requests please to glingl@aon.at.)


How to configure Screen and Turtles
-----------------------------------

The built-in default configuration mimics the appearance and behaviour
of the old turtle module in order to retain best possible
compatibility with it.

If you want to use a different configuration which better reflects the
features of this module or which better fits to your needs, e.g. for
use in a classroom, you can prepare a configuration file "turtle.cfg"
which will be read at import time and modify the configuration
according to its settings.

The built in configuration would correspond to the following
"turtle.cfg":

   width = 0.5
   height = 0.75
   leftright = None
   topbottom = None
   canvwidth = 400
   canvheight = 300
   mode = standard
   colormode = 1.0
   delay = 10
   undobuffersize = 1000
   shape = classic
   pencolor = black
   fillcolor = black
   resizemode = noresize
   visible = True
   language = english
   exampleturtle = turtle
   examplescreen = screen
   title = Python Turtle Graphics
   using_IDLE = False

Short explanation of selected entries:

* The first four lines correspond to the arguments of the
  "Screen.setup" method.

* Line 5 and 6 correspond to the arguments of the method
  "Screen.screensize".

* *shape* can be any of the built-in shapes, e.g: arrow, turtle, etc.
  For more info try "help(shape)".

* If you want to use no fill color (i.e. make the turtle transparent),
  you have to write "fillcolor = """ (but all nonempty strings must
  not have quotes in the cfg file).

* If you want to reflect the turtle its state, you have to use
  "resizemode = auto".

* If you set e.g. "language = italian" the docstringdict
  "turtle_docstringdict_italian.py" will be loaded at import time (if
  present on the import path, e.g. in the same directory as "turtle".

* The entries *exampleturtle* and *examplescreen* define the names of
  these objects as they occur in the docstrings.  The transformation
  of method-docstrings to function-docstrings will delete these names
  from the docstrings.

* *using_IDLE*: Set this to "True" if you regularly work with IDLE and
  its -n switch ("no subprocess").  This will prevent "exitonclick()"
  to enter the mainloop.

There can be a "turtle.cfg" file in the directory where "turtle" is
stored and an additional one in the current working directory.  The
latter will override the settings of the first one.

The "Lib/turtledemo" directory contains a "turtle.cfg" file.  You can
study it as an example and see its effects when running the demos
(preferably not from within the demo-viewer).


"turtledemo" --- Demo scripts
=============================

The "turtledemo" package includes a set of demo scripts.  These
scripts can be run and viewed using the supplied demo viewer as
follows:

   python -m turtledemo

Alternatively, you can run the demo scripts individually.  For
example,

   python -m turtledemo.bytedesign

The "turtledemo" package directory contains:

* A demo viewer "__main__.py" which can be used to view the sourcecode
  of the scripts and run them at the same time.

* Multiple scripts demonstrating different features of the "turtle"
  module.  Examples can be accessed via the Examples menu.  They can
  also be run standalone.

* A "turtle.cfg" file which serves as an example of how to write and
  use such files.

The demo scripts are:

+------------------+--------------------------------+-------------------------+
| Nazwa            | Opis                           | Features                |
|==================|================================|=========================|
| bytedesign       | complex classical turtle       | "tracer()", delay,      |
|                  | graphics pattern               | "update()"              |
+------------------+--------------------------------+-------------------------+
| chaos            | graphs Verhulst dynamics,      | world coordinates       |
|                  | shows that computer's          |                         |
|                  | computations can generate      |                         |
|                  | results sometimes against the  |                         |
|                  | common sense expectations      |                         |
+------------------+--------------------------------+-------------------------+
| clock            | analog clock showing time of   | turtles as clock's      |
|                  | your computer                  | hands, ontimer          |
+------------------+--------------------------------+-------------------------+
| colormixer       | experiment with r, g, b        | "ondrag()"              |
+------------------+--------------------------------+-------------------------+
| forest           | 3 breadth-first trees          | randomization           |
+------------------+--------------------------------+-------------------------+
| fractalcurves    | Hilbert & Koch curves          | recursion               |
+------------------+--------------------------------+-------------------------+
| lindenmayer      | ethnomathematics (indian       | L-System                |
|                  | kolams)                        |                         |
+------------------+--------------------------------+-------------------------+
| minimal_hanoi    | Towers of Hanoi                | Rectangular Turtles as  |
|                  |                                | Hanoi discs (shape,     |
|                  |                                | shapesize)              |
+------------------+--------------------------------+-------------------------+
| nim              | play the classical nim game    | turtles as nimsticks,   |
|                  | with three heaps of sticks     | event driven (mouse,    |
|                  | against the computer.          | keyboard)               |
+------------------+--------------------------------+-------------------------+
| paint            | super minimalistic drawing     | "onclick()"             |
|                  | program                        |                         |
+------------------+--------------------------------+-------------------------+
| peace            | elementary                     | turtle: appearance and  |
|                  |                                | animation               |
+------------------+--------------------------------+-------------------------+
| penrose          | aperiodic tiling with kites    | "stamp()"               |
|                  | and darts                      |                         |
+------------------+--------------------------------+-------------------------+
| planet_and_moon  | simulation of gravitational    | compound shapes,        |
|                  | system                         | "Vec2D"                 |
+------------------+--------------------------------+-------------------------+
| rosette          | a pattern from the wikipedia   | "clone()", "undo()"     |
|                  | article on turtle graphics     |                         |
+------------------+--------------------------------+-------------------------+
| round_dance      | dancing turtles rotating       | compound shapes, clone  |
|                  | pairwise in opposite direction | shapesize, tilt,        |
|                  |                                | get_shapepoly, update   |
+------------------+--------------------------------+-------------------------+
| sorting_animate  | visual demonstration of        | simple alignment,       |
|                  | different sorting methods      | randomization           |
+------------------+--------------------------------+-------------------------+
| tree             | a (graphical) breadth first    | "clone()"               |
|                  | tree (using generators)        |                         |
+------------------+--------------------------------+-------------------------+
| two_canvases     | simple design                  | turtles on two canvases |
+------------------+--------------------------------+-------------------------+
| yinyang          | another elementary example     | "circle()"              |
+------------------+--------------------------------+-------------------------+

Have fun!


Changes since Python 2.6
========================

* The methods "Turtle.tracer", "Turtle.window_width" and
  "Turtle.window_height" have been eliminated. Methods with these
  names and functionality are now available only as methods of
  "Screen". The functions derived from these remain available. (In
  fact already in Python 2.6 these methods were merely duplications of
  the corresponding "TurtleScreen"/"Screen" methods.)

* The method "Turtle.fill()" has been eliminated. The behaviour of
  "begin_fill()" and "end_fill()" have changed slightly: now every
  filling process must be completed with an "end_fill()" call.

* A method "Turtle.filling" has been added. It returns a boolean
  value: "True" if a filling process is under way, "False" otherwise.
  This behaviour corresponds to a "fill()" call without arguments in
  Python 2.6.


Changes since Python 3.0
========================

* The "Turtle" methods "shearfactor()", "shapetransform()" and
  "get_shapepoly()" have been added. Thus the full range of regular
  linear transforms is now available for transforming turtle shapes.
  "tiltangle()" has been enhanced in functionality: it now can be used
  to get or set the tilt angle. "settiltangle()" has been deprecated.

* The "Screen" method "onkeypress()" has been added as a complement to
  "onkey()". As the latter binds actions to the key release event, an
  alias: "onkeyrelease()" was also added for it.

* The method "Screen.mainloop" has been added, so there is no longer a
  need to use the standalone "mainloop()" function when working with
  "Screen" and "Turtle" objects.

* Two input methods have been added: "Screen.textinput" and
  "Screen.numinput". These pop up input dialogs and return strings and
  numbers respectively.

* Two example scripts "tdemo_nim.py" and "tdemo_round_dance.py" have
  been added to the "Lib/turtledemo" directory.
