[3.13] pythongh-138772: Fix and improve documentation for turtle color functions (pythonGH-139325) (pythonGH-140048)

Use multiple signatures for clarity.
Explain different forms of bgcolor() in details.
Fix outdated docstrings.
(cherry picked from commit 525dcfe)

Co-authored-by: Serhiy Storchaka <[email protected]>

Author: miss-islington

Doc/library/turtle.rst

@@ -743,13 +743,17 @@ Turtle motion
       180.0
 
 
-.. function:: dot(size=None, *color)
+.. function:: dot()
+              dot(size)
+              dot(color, /)
+              dot(size, color, /)
+              dot(size, r, g, b, /)
 
    :param size: an integer >= 1 (if given)
    :param color: a colorstring or a numeric color tuple
 
    Draw a circular dot with diameter *size*, using *color*.  If *size* is
-   not given, the maximum of pensize+4 and 2*pensize is used.
+   not given, the maximum of ``pensize+4`` and ``2*pensize`` is used.
 
 
    .. doctest::
@@ -1118,7 +1122,9 @@ Drawing state
 Color control
 ~~~~~~~~~~~~~
 
-.. function:: pencolor(*args)
+.. function:: pencolor()
+              pencolor(color, /)
+              pencolor(r, g, b, /)
 
    Return or set the pencolor.
 
@@ -1127,7 +1133,7 @@ Color control
    ``pencolor()``
       Return the current pencolor as color specification string or
       as a tuple (see example).  May be used as input to another
-      color/pencolor/fillcolor call.
+      color/pencolor/fillcolor/bgcolor call.
 
    ``pencolor(colorstring)``
       Set pencolor to *colorstring*, which is a Tk color specification string,
@@ -1167,7 +1173,9 @@ Color control
       (50.0, 193.0, 143.0)
 
 
-.. function:: fillcolor(*args)
+.. function:: fillcolor()
+              fillcolor(color, /)
+              fillcolor(r, g, b, /)
 
    Return or set the fillcolor.
 
@@ -1176,7 +1184,7 @@ Color control
    ``fillcolor()``
       Return the current fillcolor as color specification string, possibly
       in tuple format (see example).  May be used as input to another
-      color/pencolor/fillcolor call.
+      color/pencolor/fillcolor/bgcolor call.
 
    ``fillcolor(colorstring)``
       Set fillcolor to *colorstring*, which is a Tk color specification string,
@@ -1210,7 +1218,10 @@ Color control
       (255.0, 255.0, 255.0)
 
 
-.. function:: color(*args)
+.. function:: color()
+              color(color, /)
+              color(r, g, b, /)
+              color(pencolor, fillcolor, /)
 
    Return or set pencolor and fillcolor.
 
@@ -1796,13 +1807,32 @@ Most of the examples in this section refer to a TurtleScreen instance called
 Window control
 --------------
 
-.. function:: bgcolor(*args)
+.. function:: bgcolor()
+              bgcolor(color, /)
+              bgcolor(r, g, b, /)
 
-   :param args: a color string or three numbers in the range 0..colormode or a
-                3-tuple of such numbers
+   Return or set the background color of the TurtleScreen.
 
+   Four input formats are allowed:
+
+   ``bgcolor()``
+      Return the current background color as color specification string or
+      as a tuple (see example).  May be used as input to another
+      color/pencolor/fillcolor/bgcolor call.
+
+   ``bgcolor(colorstring)``
+      Set the background color to *colorstring*, which is a Tk color
+      specification string, such as ``"red"``, ``"yellow"``, or ``"#33cc8c"``.
 
-   Set or return background color of the TurtleScreen.
+   ``bgcolor((r, g, b))``
+      Set the background color to the RGB color represented by the tuple of
+      *r*, *g*, and *b*.
+      Each of *r*, *g*, and *b* must be in the range 0..colormode, where
+      colormode is either 1.0 or 255 (see :func:`colormode`).
+
+   ``bgcolor(r, g, b)``
+      Set the background color to the RGB color represented by *r*, *g*, and *b*.  Each of
+      *r*, *g*, and *b* must be in the range 0..colormode.
 
    .. doctest::
       :skipif: _tkinter is None

Lib/turtle.py

@@ -1213,16 +1213,32 @@ def turtles(self):
     def bgcolor(self, *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.
+        Four input formats are allowed:
+          - bgcolor()
+            Return the current background color as color specification
+            string or as a tuple (see example).  May be used as input
+            to another color/pencolor/fillcolor/bgcolor call.
+          - bgcolor(colorstring)
+            Set the background color to colorstring, which is a Tk color
+            specification string, such as "red", "yellow", or "#33cc8c".
+          - bgcolor((r, g, b))
+            Set the background color to the RGB color represented by
+            the tuple of r, g, and b.  Each of r, g, and b must be in
+            the range 0..colormode, where colormode is either 1.0 or 255
+            (see colormode()).
+          - bgcolor(r, g, b)
+            Set the background color to the RGB color represented by
+            r, g, and b.  Each of r, g, and b must be in the range
+            0..colormode.
 
         Example (for a TurtleScreen instance named screen):
         >>> screen.bgcolor("orange")
         >>> screen.bgcolor()
         'orange'
-        >>> screen.bgcolor(0.5,0,0.5)
+        >>> colormode(255)
+        >>> screen.bgcolor('#800080')
         >>> screen.bgcolor()
-        '#800080'
+        (128.0, 0.0, 128.0)
         """
         if args:
             color = self._colorstr(args)
@@ -1624,7 +1640,7 @@ def forward(self, distance):
 
         Example (for a Turtle instance named turtle):
         >>> turtle.position()
-        (0.00, 0.00)
+        (0.00,0.00)
         >>> turtle.forward(25)
         >>> turtle.position()
         (25.00,0.00)
@@ -1647,10 +1663,10 @@ def back(self, distance):
 
         Example (for a Turtle instance named turtle):
         >>> turtle.position()
-        (0.00, 0.00)
+        (0.00,0.00)
         >>> turtle.backward(30)
         >>> turtle.position()
-        (-30.00, 0.00)
+        (-30.00,0.00)
         """
         self._go(-distance)
 
@@ -1757,7 +1773,7 @@ def goto(self, x, y=None):
         Example (for a Turtle instance named turtle):
         >>> tp = turtle.pos()
         >>> tp
-        (0.00, 0.00)
+        (0.00,0.00)
         >>> turtle.setpos(60,30)
         >>> turtle.pos()
         (60.00,30.00)
@@ -1837,7 +1853,7 @@ def distance(self, x, y=None):
 
         Example (for a Turtle instance named turtle):
         >>> turtle.pos()
-        (0.00, 0.00)
+        (0.00,0.00)
         >>> turtle.distance(30,40)
         50.0
         >>> pen = Turtle()
@@ -2176,19 +2192,17 @@ def color(self, *args):
 
         Arguments:
         Several input formats are allowed.
-        They use 0, 1, 2, or 3 arguments as follows:
-
-        color()
-            Return the current pencolor and the current fillcolor
-            as a pair of color specification strings as are returned
-            by pencolor and fillcolor.
-        color(colorstring), color((r,g,b)), color(r,g,b)
-            inputs as in pencolor, set both, fillcolor and pencolor,
+        They use 0 to 3 arguments as follows:
+          - color()
+            Return the current pencolor and the current fillcolor as
+            a pair of color specification strings or tuples as returned
+            by pencolor() and fillcolor().
+          - color(colorstring), color((r,g,b)), color(r,g,b)
+            Inputs as in pencolor(), set both, fillcolor and pencolor,
             to the given value.
-        color(colorstring1, colorstring2),
-        color((r1,g1,b1), (r2,g2,b2))
-            equivalent to pencolor(colorstring1) and fillcolor(colorstring2)
-            and analogously, if the other input format is used.
+          - color(colorstring1, colorstring2), color((r1,g1,b1), (r2,g2,b2))
+            Equivalent to pencolor(colorstring1) and fillcolor(colorstring2)
+            and analogously if the other input format is used.
 
         If turtleshape is a polygon, outline and interior of that polygon
         is drawn with the newly set colors.
@@ -2199,9 +2213,9 @@ def color(self, *args):
         >>> turtle.color()
         ('red', 'green')
         >>> colormode(255)
-        >>> color((40, 80, 120), (160, 200, 240))
+        >>> color(('#285078', '#a0c8f0'))
         >>> color()
-        ('#285078', '#a0c8f0')
+        ((40.0, 80.0, 120.0), (160.0, 200.0, 240.0))
         """
         if args:
             l = len(args)
@@ -2223,28 +2237,32 @@ def pencolor(self, *args):
         Arguments:
         Four input formats are allowed:
           - pencolor()
-            Return the current pencolor as color specification string,
-            possibly in hex-number format (see example).
-            May be used as input to another color/pencolor/fillcolor call.
+            Return the current pencolor as color specification string or
+            as a tuple (see example).  May be used as input to another
+            color/pencolor/fillcolor/bgcolor call.
           - pencolor(colorstring)
-            s is a Tk color specification string, such as "red" or "yellow"
+            Set pencolor to colorstring, which is a Tk color
+            specification string, such as "red", "yellow", or "#33cc8c".
           - pencolor((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..colormode,
-            where colormode is either 1.0 or 255
+            Set pencolor to the RGB color represented by the tuple of
+            r, g, and b.  Each of r, g, and b must be in the range
+            0..colormode, where colormode is either 1.0 or 255 (see
+            colormode()).
           - pencolor(r, g, b)
-            r, g, and b represent an RGB color, and each of r, g, and b
-            are in the range 0..colormode
+            Set pencolor to the RGB color represented by r, g, and b.
+            Each of r, g, and b must be in the range 0..colormode.
 
         If turtleshape is a polygon, the outline of that polygon is drawn
         with the newly set pencolor.
 
         Example (for a Turtle instance named turtle):
         >>> turtle.pencolor('brown')
-        >>> tup = (0.2, 0.8, 0.55)
-        >>> turtle.pencolor(tup)
         >>> turtle.pencolor()
-        '#33cc8c'
+        'brown'
+        >>> colormode(255)
+        >>> turtle.pencolor('#32c18f')
+        >>> turtle.pencolor()
+        (50.0, 193.0, 143.0)
         """
         if args:
             color = self._colorstr(args)
@@ -2261,26 +2279,31 @@ def fillcolor(self, *args):
         Four input formats are allowed:
           - fillcolor()
             Return the current fillcolor as color specification string,
-            possibly in hex-number format (see example).
-            May be used as input to another color/pencolor/fillcolor call.
+            possibly in tuple format (see example).  May be used as
+            input to another color/pencolor/fillcolor/bgcolor call.
           - fillcolor(colorstring)
-            s is a Tk color specification string, such as "red" or "yellow"
+            Set fillcolor to colorstring, which is a Tk color
+            specification string, such as "red", "yellow", or "#33cc8c".
           - fillcolor((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..colormode,
-            where colormode is either 1.0 or 255
+            Set fillcolor to the RGB color represented by the tuple of
+            r, g, and b.  Each of r, g, and b must be in the range
+            0..colormode, where colormode is either 1.0 or 255 (see
+            colormode()).
           - fillcolor(r, g, b)
-            r, g, and b represent an RGB color, and each of r, g, and b
-            are in the range 0..colormode
+            Set fillcolor to the RGB color represented by r, g, and b.
+            Each of r, g, and b must be in the range 0..colormode.
 
         If turtleshape is a polygon, the interior of that polygon is drawn
         with the newly set fillcolor.
 
         Example (for a Turtle instance named turtle):
         >>> turtle.fillcolor('violet')
-        >>> col = turtle.pencolor()
-        >>> turtle.fillcolor(col)
-        >>> turtle.fillcolor(0, .5, 0)
+        >>> turtle.fillcolor()
+        'violet'
+        >>> colormode(255)
+        >>> turtle.fillcolor('#ffffff')
+        >>> turtle.fillcolor()
+        (255.0, 255.0, 255.0)
         """
         if args:
             color = self._colorstr(args)