Support IntervalDtype in cudf.from_pandas (#16014)

Noticed while running the pandas test suite against `cudf.pandas`

Authors:
  - Matthew Roeschke (https://github.com/mroeschke)

Approvers:
  - Bradley Dice (https://github.com/bdice)
  - Lawrence Mitchell (https://github.com/wence-)
  - GALI PREM SAGAR (https://github.com/galipremsagar)

URL: #16014

python/cudf/cudf/core/dataframe.py

@@ -8072,11 +8072,11 @@ def from_pandas(obj, nan_as_null=no_default):
         return cudf.Index.from_pandas(obj, nan_as_null=nan_as_null)
     elif isinstance(obj, pd.CategoricalDtype):
         return cudf.CategoricalDtype.from_pandas(obj)
+    elif isinstance(obj, pd.IntervalDtype):
+        return cudf.IntervalDtype.from_pandas(obj)
     else:
         raise TypeError(
-            "from_pandas only accepts Pandas Dataframes, Series, "
-            "Index, RangeIndex and MultiIndex objects. "
-            "Got %s" % type(obj)
+            f"from_pandas unsupported for object of type {type(obj).__name__}"
         )
 
 

python/cudf/cudf/tests/test_interval.py

@@ -181,3 +181,10 @@ def test_interval_with_datetime(tz, box):
     else:
         with pytest.raises(NotImplementedError):
             cudf.from_pandas(pobj)
+
+
+def test_from_pandas_intervaldtype():
+    dtype = pd.IntervalDtype("int64", closed="left")
+    result = cudf.from_pandas(dtype)
+    expected = cudf.IntervalDtype("int64", closed="left")
+    assert_eq(result, expected)