BUG: Restrict Timestamp(nanosecond=...) to [0, 999] (pandas-dev#48691)

Author: mroeschke

doc/source/whatsnew/v1.6.0.rst

@@ -115,9 +115,11 @@ See :ref:`install.dependencies` and :ref:`install.optional_dependencies` for mor
 
 Other API changes
 ^^^^^^^^^^^^^^^^^
+- Passing ``nanoseconds`` greater than 999 or less than 0 in :class:`Timestamp` now raises a ``ValueError`` (:issue:`48538`, :issue:`48255`)
 - :func:`read_csv`: specifying an incorrect number of columns with ``index_col`` of now raises ``ParserError`` instead of ``IndexError`` when using the c parser.
 -
 
+
 .. ---------------------------------------------------------------------------
 .. _whatsnew_160.deprecations:
 

pandas/_libs/tslibs/timestamps.pyx

@@ -1682,7 +1682,13 @@ class Timestamp(_Timestamp):
             )
             # Once this deprecation is enforced, we can do
             #  return Timestamp(ts_input).tz_localize(tzobj)
-        ts = convert_to_tsobject(ts_input, tzobj, unit, 0, 0, nanosecond or 0)
+
+        if nanosecond is None:
+            nanosecond = 0
+        elif not (999 >= nanosecond >= 0):
+            raise ValueError("nanosecond must be in 0..999")
+
+        ts = convert_to_tsobject(ts_input, tzobj, unit, 0, 0, nanosecond)
 
         if ts.value == NPY_NAT:
             return NaT

pandas/tests/scalar/timestamp/test_constructors.py

@@ -677,3 +677,10 @@ def test_constructor_missing_keyword(kwargs):
 
     with pytest.raises(TypeError, match=msg):
         Timestamp(**kwargs)
+
+
+@pytest.mark.parametrize("nano", [-1, 1000])
+def test_timestamp_nano_range(nano):
+    # GH 48255
+    with pytest.raises(ValueError, match="nanosecond must be in 0..999"):
+        Timestamp(year=2022, month=1, day=1, nanosecond=nano)