handle np versions, separate unary/binary path

xarray/tests/test_ufuncs.py

@@ -196,8 +196,11 @@ def setUp(self):
     @pytest.mark.filterwarnings("ignore::RuntimeWarning")
     @pytest.mark.parametrize("name", xu.__all__)
     def test_ufuncs(self, name, request):
-        np_func = getattr(np, name)
         xu_func = getattr(xu, name)
+        if isinstance(xu_func, xu._UnavailableUfunc):
+            pytest.xfail(f"Ufunc {name} is not available in numpy {np.__version__}.")
+
+        np_func = getattr(np, name)
 
         if name == "isnat":
             args = (self.xt,)

xarray/ufuncs.py

@@ -41,16 +41,40 @@ def get_array_namespace(*args):
     return next(iter(xps)) if len(xps) else np
 
 
-class _UFuncDispatcher:
-    """Wrapper for dispatching ufuncs."""
+class _UnaryUfunc:
+    """Wrapper for dispatching unary ufuncs."""
 
     def __init__(self, name):
         self._name = name
 
-    def __call__(self, *args, **kwargs):
-        xp = get_array_namespace(*args)
+    def __call__(self, x, **kwargs):
+        xp = get_array_namespace(x)
         func = getattr(xp, self._name)
-        return xr.apply_ufunc(func, *args, dask="allowed", **kwargs)
+        return xr.apply_ufunc(func, x, dask="allowed", **kwargs)
+
+
+class _BinaryUfunc:
+    """Wrapper for dispatching binary ufuncs."""
+
+    def __init__(self, name):
+        self._name = name
+
+    def __call__(self, x, y, **kwargs):
+        xp = get_array_namespace(x, y)
+        func = getattr(xp, self._name)
+        return xr.apply_ufunc(func, x, y, dask="allowed", **kwargs)
+
+
+class _UnavailableUfunc:
+    """Wrapper for unimplemented ufuncs in older numpy versions."""
+
+    def __init__(self, name):
+        self._name = name
+
+    def __call__(self, *args, **kwargs):
+        raise NotImplementedError(
+            f"Ufunc {self._name} is not available in numpy {np.__version__}."
+        )
 
 
 def _skip_signature(doc, name):
@@ -90,7 +114,18 @@ def _dedent(doc):
 
 
 def _create_op(name):
-    func = _UFuncDispatcher(name)
+    if not hasattr(np, name):
+        # handle older numpy versions with missing array api standard aliases
+        if np.lib.NumpyVersion(np.__version__) < "2.0.0":
+            return _UnavailableUfunc(name)
+        raise ValueError(f"'{name}' is not a valid numpy function")
+
+    np_func = getattr(np, name)
+    if hasattr(np_func, "nin") and np_func.nin == 2:
+        func = _BinaryUfunc(name)
+    else:
+        func = _UnaryUfunc(name)
+
     func.__name__ = name
     doc = getattr(np, name).__doc__
 
@@ -111,7 +146,7 @@ def _create_op(name):
 # Ufuncs that use core dimensions or product multiple output arrays are
 # not currently supported, and left commented below.
 
-# unary
+# UNARY
 abs = _create_op("abs")
 absolute = _create_op("absolute")
 acos = _create_op("acos")
@@ -142,7 +177,7 @@ def _create_op(name):
 expm1 = _create_op("expm1")
 fabs = _create_op("fabs")
 floor = _create_op("floor")
-# frexp
+# frexp = _create_op("frexp")
 invert = _create_op("invert")
 isfinite = _create_op("isfinite")
 isinf = _create_op("isinf")
@@ -153,7 +188,7 @@ def _create_op(name):
 log1p = _create_op("log1p")
 log2 = _create_op("log2")
 logical_not = _create_op("logical_not")
-# modf
+# modf = _create_op("modf")
 negative = _create_op("negative")
 positive = _create_op("positive")
 rad2deg = _create_op("rad2deg")
@@ -171,7 +206,7 @@ def _create_op(name):
 tanh = _create_op("tanh")
 trunc = _create_op("trunc")
 
-# binary
+# BINARY
 add = _create_op("add")
 arctan2 = _create_op("arctan2")
 atan2 = _create_op("atan2")
@@ -182,7 +217,7 @@ def _create_op(name):
 bitwise_xor = _create_op("bitwise_xor")
 copysign = _create_op("copysign")
 divide = _create_op("divide")
-# divmod
+# divmod = _create_op("divmod")
 equal = _create_op("equal")
 float_power = _create_op("float_power")
 floor_divide = _create_op("floor_divide")
@@ -204,7 +239,7 @@ def _create_op(name):
 logical_and = _create_op("logical_and")
 logical_or = _create_op("logical_or")
 logical_xor = _create_op("logical_xor")
-# matmul
+# matmul = _create_op("matmul")
 maximum = _create_op("maximum")
 minimum = _create_op("minimum")
 mod = _create_op("mod")
@@ -217,7 +252,7 @@ def _create_op(name):
 right_shift = _create_op("right_shift")
 subtract = _create_op("subtract")
 true_divide = _create_op("true_divide")
-# vecdot
+# vecdot = _create_op("vecdot")
 
 # elementwise non-ufunc
 angle = _create_op("angle")