BUG: Raise TypeError for mismatched signed/unsigned dtypes in IntervalIndex.from_arrays

Author: Aniketsy

pandas/core/indexes/interval.py

@@ -310,6 +310,20 @@ def from_arrays(
         copy: bool = False,
         dtype: Dtype | None = None,
     ) -> IntervalIndex:
+        # Check for mismatched signed/unsigned integer dtypes
+        left_dtype = getattr(left, "dtype", None)
+        right_dtype = getattr(right, "dtype", None)
+        if (
+            left_dtype is not None
+            and right_dtype is not None
+            and left_dtype.kind in "iu"
+            and right_dtype.kind in "iu"
+            and left_dtype.kind != right_dtype.kind
+        ):
+            raise TypeError(
+                f"Left and right arrays must have matching signedness. "
+                f"Got {left_dtype} and {right_dtype}."
+            )
         with rewrite_exception("IntervalArray", cls.__name__):
             array = IntervalArray.from_arrays(
                 left, right, closed, copy=copy, dtype=dtype

pandas/tests/indexes/interval/test_interval.py

@@ -882,6 +882,14 @@ def test_is_all_dates(self):
         assert not year_2017_index._is_all_dates
 
 
+def test_from_arrays_mismatched_signedness_raises():
+    # GH 55715
+    left = np.array([0, 1, 2], dtype="int64")
+    right = np.array([1, 2, 3], dtype="uint64")
+    with pytest.raises(TypeError, match="matching signedness"):
+        IntervalIndex.from_arrays(left, right)
+
+
 def test_dir():
     # GH#27571 dir(interval_index) should not raise
     index = IntervalIndex.from_arrays([0, 1], [1, 2])