turtle: various improvements (#3677)

* turtle: add None and default value to overloads
* turtle: add default value to write_docstringdict
* turtle: fix _Screen.setup

stdlib/2and3/turtle.pyi

@@ -47,13 +47,13 @@ class TurtleScreen(TurtleScreenBase):
     def __init__(self, cv: Canvas, mode: str = ..., colormode: float = ..., delay: int = ...) -> None: ...
     def clear(self) -> None: ...
     @overload
-    def mode(self) -> str: ...
+    def mode(self, mode: None = ...) -> str: ...
     @overload
     def mode(self, mode: str) -> None: ...
     def setworldcoordinates(self, llx: float, lly: float, urx: float, ury: float) -> None: ...
     def register_shape(self, name: str, shape: Union[_PolygonCoords, Shape, None] = ...) -> None: ...
     @overload
-    def colormode(self) -> float: ...
+    def colormode(self, cmode: None = ...) -> float: ...
     @overload
     def colormode(self, cmode: float) -> None: ...
     def reset(self) -> None: ...
@@ -65,11 +65,11 @@ class TurtleScreen(TurtleScreenBase):
     @overload
     def bgcolor(self, r: float, g: float, b: float) -> None: ...
     @overload
-    def tracer(self) -> int: ...
+    def tracer(self, n: None = ...) -> int: ...
     @overload
     def tracer(self, n: int, delay: Optional[int] = ...) -> None: ...
     @overload
-    def delay(self) -> int: ...
+    def delay(self, delay: None = ...) -> int: ...
     @overload
     def delay(self, delay: int) -> None: ...
     def update(self) -> None: ...
@@ -82,11 +82,12 @@ class TurtleScreen(TurtleScreenBase):
     def listen(self, xdummy: Optional[float] = ..., ydummy: Optional[float] = ...) -> None: ...
     def ontimer(self, fun: Callable[[], Any], t: int = ...) -> None: ...
     @overload
-    def bgpic(self) -> str: ...
+    def bgpic(self, picname: None = ...) -> str: ...
     @overload
     def bgpic(self, picname: str) -> None: ...
     @overload
-    def screensize(self) -> Tuple[int, int]: ...
+    def screensize(self, canvwidth: None = ..., canvheight: None = ..., bg: None = ...) -> Tuple[int, int]: ...
+    # Looks like if self.cv is not a ScrolledCanvas, this could return a tuple as well
     @overload
     def screensize(self, canvwidth: int, canvheight: int, bg: Optional[_Color] = ...) -> None: ...
     onscreenclick = onclick
@@ -114,18 +115,18 @@ class TNavigator(object):
     def xcor(self) -> float: ...
     def ycor(self) -> float: ...
     @overload
-    def goto(self, x: Tuple[float, float]) -> None: ...
+    def goto(self, x: Tuple[float, float], y: None = ...) -> None: ...
     @overload
     def goto(self, x: float, y: float) -> None: ...
     def home(self) -> None: ...
     def setx(self, x: float) -> None: ...
     def sety(self, y: float) -> None: ...
     @overload
-    def distance(self, x: Union[TNavigator, Tuple[float, float]]) -> float: ...
+    def distance(self, x: Union[TNavigator, Tuple[float, float]], y: None = ...) -> float: ...
     @overload
     def distance(self, x: float, y: float) -> float: ...
     @overload
-    def towards(self, x: Union[TNavigator, Tuple[float, float]]) -> float: ...
+    def towards(self, x: Union[TNavigator, Tuple[float, float]], y: None = ...) -> float: ...
     @overload
     def towards(self, x: float, y: float) -> float: ...
     def heading(self) -> float: ...
@@ -145,18 +146,18 @@ class TNavigator(object):
 class TPen(object):
     def __init__(self, resizemode: str = ...) -> None: ...
     @overload
-    def resizemode(self) -> str: ...
+    def resizemode(self, rmode: None = ...) -> str: ...
     @overload
     def resizemode(self, rmode: str) -> None: ...
     @overload
-    def pensize(self) -> int: ...
+    def pensize(self, width: None = ...) -> int: ...
     @overload
     def pensize(self, width: int) -> None: ...
     def penup(self) -> None: ...
     def pendown(self) -> None: ...
     def isdown(self) -> bool: ...
     @overload
-    def speed(self) -> int: ...
+    def speed(self, speed: None = ...) -> int: ...
     @overload
     def speed(self, speed: _Speed) -> None: ...
     @overload
@@ -208,7 +209,7 @@ class RawTurtle(TPen, TNavigator):
     def clear(self) -> None: ...
     def clone(self: _T) -> _T: ...
     @overload
-    def shape(self) -> str: ...
+    def shape(self, name: None = ...) -> str: ...
     @overload
     def shape(self, name: str) -> None: ...
     # Unsafely overlaps when no arguments are provided
@@ -218,7 +219,7 @@ class RawTurtle(TPen, TNavigator):
     def shapesize(self, stretch_wid: Optional[float] = ..., stretch_len: Optional[float] = ..., outline: Optional[float] = ...) -> None: ...
     if sys.version_info >= (3,):
         @overload
-        def shearfactor(self) -> float: ...
+        def shearfactor(self, shear: None = ...) -> float: ...
         @overload
         def shearfactor(self, shear: float) -> None: ...
         # Unsafely overlaps when no arguments are provided
@@ -229,7 +230,7 @@ class RawTurtle(TPen, TNavigator):
         def get_shapepoly(self) -> Optional[_PolygonCoords]: ...
     def settiltangle(self, angle: float) -> None: ...
     @overload
-    def tiltangle(self) -> float: ...
+    def tiltangle(self, angle: None = ...) -> float: ...
     @overload
     def tiltangle(self, angle: float) -> None: ...
     def tilt(self, angle: float) -> None: ...
@@ -258,7 +259,14 @@ class RawTurtle(TPen, TNavigator):
 
 class _Screen(TurtleScreen):
     def __init__(self) -> None: ...
-    def setup(self, width: int = ..., height: int = ..., startx: int = ..., starty: int = ...) -> None: ...
+    # Note int and float are interpreted differently, hence the Union instead of just float
+    def setup(
+        self,
+        width: Union[int, float] = ...,
+        height: Union[int, float] = ...,
+        startx: Optional[int] = ...,
+        starty: Optional[int] = ...
+    ) -> None: ...
     def title(self, titlestring: str) -> None: ...
     def bye(self) -> None: ...
     def exitonclick(self) -> None: ...
@@ -271,7 +279,7 @@ class Turtle(RawTurtle):
 RawPen = RawTurtle
 Pen = Turtle
 
-def write_docstringdict(filename: str) -> None: ...
+def write_docstringdict(filename: str = ...) -> None: ...
 
 # Note: it's somewhat unfortunate that we have to copy the function signatures.
 # It would be nice if we could partially reduce the redundancy by doing something
@@ -295,13 +303,13 @@ if sys.version_info >= (3,):
 
 def clear() -> None: ...
 @overload
-def mode() -> str: ...
+def mode(mode: None = ...) -> str: ...
 @overload
 def mode(mode: str) -> None: ...
 def setworldcoordinates(llx: float, lly: float, urx: float, ury: float) -> None: ...
 def register_shape(name: str, shape: Union[_PolygonCoords, Shape, None] = ...) -> None: ...
 @overload
-def colormode() -> float: ...
+def colormode(cmode: None = ...) -> float: ...
 @overload
 def colormode(cmode: float) -> None: ...
 def reset() -> None: ...
@@ -313,11 +321,11 @@ def bgcolor(color: _Color) -> None: ...
 @overload
 def bgcolor(r: float, g: float, b: float) -> None: ...
 @overload
-def tracer() -> int: ...
+def tracer(n: None = ...) -> int: ...
 @overload
 def tracer(n: int, delay: Optional[int] = ...) -> None: ...
 @overload
-def delay() -> int: ...
+def delay(delay: None = ...) -> int: ...
 @overload
 def delay(delay: int) -> None: ...
 def update() -> None: ...
@@ -330,11 +338,11 @@ def onkey(fun: Callable[[], Any], key: str) -> None: ...
 def listen(xdummy: Optional[float] = ..., ydummy: Optional[float] = ...) -> None: ...
 def ontimer(fun: Callable[[], Any], t: int = ...) -> None: ...
 @overload
-def bgpic() -> str: ...
+def bgpic(picname: None = ...) -> str: ...
 @overload
 def bgpic(picname: str) -> None: ...
 @overload
-def screensize() -> Tuple[int, int]: ...
+def screensize(canvwidth: None = ..., canvheight: None = ..., bg: None = ...) -> Tuple[int, int]: ...
 @overload
 def screensize(canvwidth: int, canvheight: int, bg: Optional[_Color] = ...) -> None: ...
 onscreenclick = onclick
@@ -357,18 +365,18 @@ def pos() -> Vec2D: ...
 def xcor() -> float: ...
 def ycor() -> float: ...
 @overload
-def goto(x: Tuple[float, float]) -> None: ...
+def goto(x: Tuple[float, float], y: None = ...) -> None: ...
 @overload
 def goto(x: float, y: float) -> None: ...
 def home() -> None: ...
 def setx(x: float) -> None: ...
 def sety(y: float) -> None: ...
 @overload
-def distance(x: Union[TNavigator, Tuple[float, float]]) -> float: ...
+def distance(x: Union[TNavigator, Tuple[float, float]], y: None = ...) -> float: ...
 @overload
 def distance(x: float, y: float) -> float: ...
 @overload
-def towards(x: Union[TNavigator, Tuple[float, float]]) -> float: ...
+def towards(x: Union[TNavigator, Tuple[float, float]], y: None = ...) -> float: ...
 @overload
 def towards(x: float, y: float) -> float: ...
 def heading() -> float: ...
@@ -387,18 +395,18 @@ seth = setheading
 # Functions copied from TPen:
 
 @overload
-def resizemode() -> str: ...
+def resizemode(rmode: None = ...) -> str: ...
 @overload
 def resizemode(rmode: str) -> None: ...
 @overload
-def pensize() -> int: ...
+def pensize(width: None = ...) -> int: ...
 @overload
 def pensize(width: int) -> None: ...
 def penup() -> None: ...
 def pendown() -> None: ...
 def isdown() -> bool: ...
 @overload
-def speed() -> int: ...
+def speed(speed: None = ...) -> int: ...
 @overload
 def speed(speed: _Speed) -> None: ...
 @overload
@@ -445,7 +453,7 @@ ht = hideturtle
 def setundobuffer(size: Optional[int]) -> None: ...
 def undobufferentries() -> int: ...
 @overload
-def shape() -> str: ...
+def shape(name: None = ...) -> str: ...
 @overload
 def shape(name: str) -> None: ...
 # Unsafely overlaps when no arguments are provided
@@ -455,7 +463,7 @@ def shapesize() -> Tuple[float, float, float]: ...  # type: ignore
 def shapesize(stretch_wid: Optional[float] = ..., stretch_len: Optional[float] = ..., outline: Optional[float] = ...) -> None: ...
 if sys.version_info >= (3,):
     @overload
-    def shearfactor() -> float: ...
+    def shearfactor(shear: None = ...) -> float: ...
     @overload
     def shearfactor(shear: float) -> None: ...
     # Unsafely overlaps when no arguments are provided
@@ -466,7 +474,7 @@ if sys.version_info >= (3,):
     def get_shapepoly() -> Optional[_PolygonCoords]: ...
 def settiltangle(angle: float) -> None: ...
 @overload
-def tiltangle() -> float: ...
+def tiltangle(angle: None = ...) -> float: ...
 @overload
 def tiltangle(angle: float) -> None: ...
 def tilt(angle: float) -> None: ...