Implement Real and Complex type aliases

The Python standard library `numbers` module defines abstract base
classes for different types of numbers, but those classes are not
suitable for type checking (python/mypy#3186),
so `astropy` should define these types itself.

astropy/units/format/base.py

@@ -8,12 +8,12 @@
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
-    from numbers import Real
     from typing import ClassVar, Literal
 
     import numpy as np
 
     from astropy.units import NamedUnit, UnitBase
+    from astropy.units.typing import Real
 
 
 class Base:

astropy/units/format/latex.py

@@ -12,10 +12,10 @@
 from . import console, utils
 
 if TYPE_CHECKING:
-    from numbers import Real
     from typing import ClassVar, Literal
 
     from astropy.units import NamedUnit, UnitBase
+    from astropy.units.typing import Real
 
 
 class Latex(console.Console):

astropy/units/format/unicode_format.py

@@ -11,10 +11,10 @@
 from . import console, utils
 
 if TYPE_CHECKING:
-    from numbers import Real
     from typing import ClassVar
 
     from astropy.units import NamedUnit
+    from astropy.units.typing import Real
 
 
 class Unicode(console.Console):

astropy/units/format/utils.py

@@ -13,10 +13,10 @@
 
 if TYPE_CHECKING:
     from collections.abc import Callable, Generator, Iterable, Sequence
-    from numbers import Real
     from typing import TypeVar
 
     from astropy.units import UnitBase
+    from astropy.units.typing import Real
 
     T = TypeVar("T")
 

astropy/units/typing.py

@@ -5,8 +5,10 @@
 __all__ = ["QuantityLike"]
 
 
+from fractions import Fraction
 from typing import TYPE_CHECKING
 
+import numpy as np
 import numpy.typing as npt
 
 from astropy.units import Quantity
@@ -64,3 +66,11 @@
 For more examples see the :mod:`numpy.typing` definition of
 :obj:`numpy.typing.ArrayLike`.
 """
+
+
+# The classes from the standard library `numbers` module are not suitable for
+# type checking (https://github.com/python/mypy/issues/3186). For now we define
+# our own number types, but if a good definition becomes available upstream
+# then we should switch to that.
+Real: TypeAlias = int | float | Fraction | np.integer | np.floating
+Complex: TypeAlias = Real | complex | np.complexfloating

astropy/units/utils.py

@@ -18,11 +18,12 @@
 
 if TYPE_CHECKING:
     from collections.abc import Generator, Sequence
-    from numbers import Complex, Real
     from typing import Literal, SupportsFloat, TypeVar
 
     from numpy.typing import ArrayLike, NDArray
 
+    from astropy.units.typing import Complex, Real
+
     from .core import UnitBase
     from .quantity import Quantity
 

docs/nitpick-exceptions

@@ -83,7 +83,6 @@ py:class a shallow copy of D
 # types
 py:class EllipsisType
 py:class ModuleType
-py:class Real
 # numpy
 py:class np.number
 # numpy.typing