Add more return types to the numbers module (#11353)

Author: AlexWaygood

stdlib/numbers.pyi

@@ -1,130 +1,154 @@
 # Note: these stubs are incomplete. The more complex type
 # signatures are currently omitted.
+#
+# Use SupportsComplex, SupportsFloat and SupportsIndex for return types in this module
+# rather than `numbers.Complex`, `numbers.Real` and `numbers.Integral`,
+# to avoid an excessive number of `type: ignore`s in subclasses of these ABCs
+# (since type checkers don't see `complex` as a subtype of `numbers.Complex`,
+# nor `float` as a subtype of `numbers.Real`, etc.)
 
+import sys
 from _typeshed import Incomplete
 from abc import ABCMeta, abstractmethod
-from typing import SupportsFloat, overload
+from typing import Literal, SupportsFloat, SupportsIndex, overload
+from typing_extensions import TypeAlias
+
+if sys.version_info >= (3, 11):
+    from typing import SupportsComplex as _SupportsComplex
+else:
+    # builtins.complex didn't have a __complex__ method on older Pythons
+    import typing
+
+    _SupportsComplex: TypeAlias = typing.SupportsComplex | complex
 
 __all__ = ["Number", "Complex", "Real", "Rational", "Integral"]
 
 class Number(metaclass=ABCMeta):
     @abstractmethod
     def __hash__(self) -> int: ...
 
+# See comment at the top of the file
+# for why some of these return types are purposefully vague
 class Complex(Number):
     @abstractmethod
     def __complex__(self) -> complex: ...
     def __bool__(self) -> bool: ...
     @property
     @abstractmethod
-    def real(self): ...
+    def real(self) -> SupportsFloat: ...
     @property
     @abstractmethod
-    def imag(self): ...
+    def imag(self) -> SupportsFloat: ...
     @abstractmethod
-    def __add__(self, other): ...
+    def __add__(self, other) -> _SupportsComplex: ...
     @abstractmethod
-    def __radd__(self, other): ...
+    def __radd__(self, other) -> _SupportsComplex: ...
     @abstractmethod
-    def __neg__(self): ...
+    def __neg__(self) -> _SupportsComplex: ...
     @abstractmethod
-    def __pos__(self): ...
-    def __sub__(self, other): ...
-    def __rsub__(self, other): ...
+    def __pos__(self) -> _SupportsComplex: ...
+    def __sub__(self, other) -> _SupportsComplex: ...
+    def __rsub__(self, other) -> _SupportsComplex: ...
     @abstractmethod
-    def __mul__(self, other): ...
+    def __mul__(self, other) -> _SupportsComplex: ...
     @abstractmethod
-    def __rmul__(self, other): ...
+    def __rmul__(self, other) -> _SupportsComplex: ...
     @abstractmethod
-    def __truediv__(self, other): ...
+    def __truediv__(self, other) -> _SupportsComplex: ...
     @abstractmethod
-    def __rtruediv__(self, other): ...
+    def __rtruediv__(self, other) -> _SupportsComplex: ...
     @abstractmethod
-    def __pow__(self, exponent): ...
+    def __pow__(self, exponent) -> _SupportsComplex: ...
     @abstractmethod
-    def __rpow__(self, base): ...
+    def __rpow__(self, base) -> _SupportsComplex: ...
     @abstractmethod
-    def __abs__(self) -> Real: ...
+    def __abs__(self) -> SupportsFloat: ...
     @abstractmethod
-    def conjugate(self): ...
+    def conjugate(self) -> _SupportsComplex: ...
     @abstractmethod
     def __eq__(self, other: object) -> bool: ...
 
+# See comment at the top of the file
+# for why some of these return types are purposefully vague
 class Real(Complex, SupportsFloat):
     @abstractmethod
     def __float__(self) -> float: ...
     @abstractmethod
-    def __trunc__(self) -> int: ...
+    def __trunc__(self) -> SupportsIndex: ...
     @abstractmethod
-    def __floor__(self) -> int: ...
+    def __floor__(self) -> SupportsIndex: ...
     @abstractmethod
-    def __ceil__(self) -> int: ...
+    def __ceil__(self) -> SupportsIndex: ...
     @abstractmethod
     @overload
-    def __round__(self, ndigits: None = None) -> int: ...
+    def __round__(self, ndigits: None = None) -> SupportsIndex: ...
     @abstractmethod
     @overload
-    def __round__(self, ndigits: int): ...
-    def __divmod__(self, other): ...
-    def __rdivmod__(self, other): ...
+    def __round__(self, ndigits: int) -> SupportsFloat: ...
+    def __divmod__(self, other) -> tuple[SupportsFloat, SupportsFloat]: ...
+    def __rdivmod__(self, other) -> tuple[SupportsFloat, SupportsFloat]: ...
     @abstractmethod
-    def __floordiv__(self, other) -> int: ...
+    def __floordiv__(self, other) -> SupportsFloat: ...
     @abstractmethod
-    def __rfloordiv__(self, other) -> int: ...
+    def __rfloordiv__(self, other) -> SupportsFloat: ...
     @abstractmethod
-    def __mod__(self, other): ...
+    def __mod__(self, other) -> SupportsFloat: ...
     @abstractmethod
-    def __rmod__(self, other): ...
+    def __rmod__(self, other) -> SupportsFloat: ...
     @abstractmethod
     def __lt__(self, other) -> bool: ...
     @abstractmethod
     def __le__(self, other) -> bool: ...
     def __complex__(self) -> complex: ...
     @property
-    def real(self): ...
+    def real(self) -> SupportsFloat: ...
     @property
-    def imag(self): ...
-    def conjugate(self): ...
+    def imag(self) -> Literal[0]: ...
+    def conjugate(self) -> SupportsFloat: ...  # type: ignore[override]
 
+# See comment at the top of the file
+# for why some of these return types are purposefully vague
 class Rational(Real):
     @property
     @abstractmethod
-    def numerator(self) -> int: ...
+    def numerator(self) -> SupportsIndex: ...
     @property
     @abstractmethod
-    def denominator(self) -> int: ...
+    def denominator(self) -> SupportsIndex: ...
     def __float__(self) -> float: ...
 
+# See comment at the top of the file
+# for why some of these return types are purposefully vague
 class Integral(Rational):
     @abstractmethod
     def __int__(self) -> int: ...
     def __index__(self) -> int: ...
     @abstractmethod
-    def __pow__(self, exponent, modulus: Incomplete | None = None): ...
+    def __pow__(self, exponent, modulus: Incomplete | None = None) -> SupportsIndex: ...  # type: ignore[override]
     @abstractmethod
-    def __lshift__(self, other): ...
+    def __lshift__(self, other) -> SupportsIndex: ...
     @abstractmethod
-    def __rlshift__(self, other): ...
+    def __rlshift__(self, other) -> SupportsIndex: ...
     @abstractmethod
-    def __rshift__(self, other): ...
+    def __rshift__(self, other) -> SupportsIndex: ...
     @abstractmethod
-    def __rrshift__(self, other): ...
+    def __rrshift__(self, other) -> SupportsIndex: ...
     @abstractmethod
-    def __and__(self, other): ...
+    def __and__(self, other) -> SupportsIndex: ...
     @abstractmethod
-    def __rand__(self, other): ...
+    def __rand__(self, other) -> SupportsIndex: ...
     @abstractmethod
-    def __xor__(self, other): ...
+    def __xor__(self, other) -> SupportsIndex: ...
     @abstractmethod
-    def __rxor__(self, other): ...
+    def __rxor__(self, other) -> SupportsIndex: ...
     @abstractmethod
-    def __or__(self, other): ...
+    def __or__(self, other) -> SupportsIndex: ...
     @abstractmethod
-    def __ror__(self, other): ...
+    def __ror__(self, other) -> SupportsIndex: ...
     @abstractmethod
-    def __invert__(self): ...
+    def __invert__(self) -> SupportsIndex: ...
     def __float__(self) -> float: ...
     @property
-    def numerator(self) -> int: ...
+    def numerator(self) -> SupportsIndex: ...
     @property
-    def denominator(self) -> int: ...
+    def denominator(self) -> Literal[1]: ...