BUG: Raise TypeError for mismatched signed/unsigned dtypes

Author: Aniketsy

pandas/core/arrays/interval.py

@@ -263,19 +263,6 @@ def __new__(
                 dtype=dtype,
             )
 
-            # Check for mismatched signed/unsigned integer dtypes after casting
-            left_dtype = left.dtype
-            right_dtype = right.dtype
-            if (
-                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}."
-                )
-
         if verify_integrity:
             cls._validate(left, right, dtype=dtype)
 
@@ -394,6 +381,18 @@ def _ensure_simple_new_inputs(
 
         dtype = IntervalDtype(left.dtype, closed=closed)
 
+        # Check for mismatched signed/unsigned integer dtypes after casting
+        left_dtype = left.dtype
+        right_dtype = right.dtype
+        if (
+            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}."
+            )
         return left, right, dtype
 
     @classmethod