BUG: is_dtype_equal(dtype, "string[pyarrow]") raises if pyarrow not installed

pandas/core/dtypes/common.py

@@ -601,7 +601,8 @@ def is_dtype_equal(source, target) -> bool:
             #  is_dtype_equal(CDT, "category") and CDT == "category"
             try:
                 src = get_dtype(source)
-                if isinstance(src, ExtensionDtype):
+                if isinstance(src, ExtensionDtype) or isinstance(src, np.dtype):
+
                     return src == target
             except (TypeError, AttributeError):
                 return False

pandas/tests/base/test_misc.py

@@ -10,6 +10,7 @@
 
 from pandas.core.dtypes.common import (
     is_categorical_dtype,
+    is_dtype_equal,
     is_object_dtype,
 )
 
@@ -150,6 +151,8 @@ def test_access_by_position(index):
     assert index[-1] == index[size - 1]
 
     msg = f"index {size} is out of bounds for axis 0 with size {size}"
+
+    assert not is_dtype_equal(index.dtype, "string[pyarrow]")
     with pytest.raises(IndexError, match=msg):
         index[size]
     msg = "single positional indexer is out-of-bounds"