Update duck_array_ops.py

Author: hmaarrfk

xarray/core/duck_array_ops.py

@@ -222,7 +222,6 @@ def asarray(data, xp=np):
 
 def as_shared_dtype(scalars_or_arrays, xp=np):
     """Cast a arrays to a shared dtype using xarray's type promotion rules."""
-    array_type_cupy = array_type("cupy")
     if any(is_extension_array_dtype(x) for x in scalars_or_arrays):
         extension_array_types = [
             x.dtype for x in scalars_or_arrays if is_extension_array_dtype(x)
@@ -234,7 +233,10 @@ def as_shared_dtype(scalars_or_arrays, xp=np):
         raise ValueError(
             f"Cannot cast arrays to shared type, found array types {[x.dtype for x in scalars_or_arrays]}"
         )
-    elif any(isinstance(x, array_type_cupy) for x in scalars_or_arrays):
+
+    # Avoid calling array_type("cupy") repeatidely in the any check
+    array_type_cupy = array_type("cupy")
+    if any(isinstance(x, array_type_cupy) for x in scalars_or_arrays):
         import cupy as cp
 
         arrays = [asarray(x, xp=cp) for x in scalars_or_arrays]