Fix BUG: overflow on pd.Timedelta(nanoseconds=) constructor

doc/source/whatsnew/v1.1.0.rst

@@ -234,7 +234,7 @@ Numeric
 Conversion
 ^^^^^^^^^^
 - Bug in :class:`Series` construction from NumPy array with big-endian ``datetime64`` dtype (:issue:`29684`)
--
+- Bug in :class:`Timedelta` construction with large nanoseconds keyword value (:issue:`34202`)
 -
 
 Strings

pandas/_libs/tslibs/timedeltas.pyx

@@ -1198,7 +1198,7 @@ class Timedelta(_Timedelta):
 
             kwargs = {key: _to_py_int_float(kwargs[key]) for key in kwargs}
 
-            nano = np.timedelta64(kwargs.pop('nanoseconds', 0), 'ns')
+            nano = convert_to_timedelta64(kwargs.pop('nanoseconds', 0), 'ns')
             try:
                 value = nano + convert_to_timedelta64(timedelta(**kwargs),
                                                       'ns')

pandas/tests/tslibs/test_timedeltas.py

@@ -28,3 +28,9 @@ def test_delta_to_nanoseconds_error():
 
     with pytest.raises(TypeError, match="<class 'numpy.ndarray'>"):
         delta_to_nanoseconds(obj)
+
+
+def test_huge_nanoseconds_overflow():
+    # GH 32402
+    assert delta_to_nanoseconds(Timedelta(1e10)) == 1e10
+    assert delta_to_nanoseconds(Timedelta(nanoseconds=1e10)) == 1e10