Added testing for NAT

Author: MomIsBestFriend

pandas/_libs/tslibs/nattype.pyx

@@ -426,6 +426,7 @@ class NaTType(_NaT):
     toordinal = _make_error_func('toordinal', datetime)
     tzname = _make_error_func('tzname', datetime)
     utcoffset = _make_error_func('utcoffset', datetime)
+    fromisocalendar = _make_error_func('fromisocalendar', datetime)
 
     # ----------------------------------------------------------------------
     # The remaining methods have docstrings copy/pasted from the analogous
@@ -467,36 +468,7 @@ class NaTType(_NaT):
         Return a new Timestamp representing UTC day and time.
         """
     )
-    fromisocalendar = _make_error_func('fromisocalendar',  # noqa:E128
-        """
-        Timestamp.fromisocalendar(year, week, day)
-
-        Return a new Timestamp corresponding to the
-        ISO calendar date specified by year, week and day.
 
-        Parameters
-        ----------
-        year: int
-            Representing a year.
-        week : int
-            Value between 1-53, representing a week in a year.
-        day : int
-            Value between 1-7, representing a day in the week.
-
-        Returns
-        -------
-        Timestamp
-
-        Raises
-        ------
-        NotImplementedError
-            If the running platform is a Python version earlier than 3.8
-
-        Notes
-        -----
-        `week` can have the value of 53, only when year is a leap year.
-        """
-    )
     timestamp = _make_error_func('timestamp',  # noqa:E128
         """Return POSIX timestamp as float.""")
 

pandas/_libs/tslibs/timestamps.pyx

@@ -336,45 +336,6 @@ class Timestamp(_Timestamp):
         """
         return cls(datetime.combine(date, time))
 
-    @classmethod
-    def fromisocalendar(cls, year, week, day):
-        """
-        Timestamp.fromisocalendar(year, week, day)
-
-        Return a new Timestamp corresponding to the
-        ISO calendar date specified by year, week and day.
-
-        Parameters
-        ----------
-        year: int
-            Representing a year.
-        week : int
-            Value between 1-53, representing a week in a year.
-        day : int
-            Value between 1-7, representing a day in the week.
-
-        Returns
-        -------
-        Timestamp
-
-        Raises
-        ------
-        NotImplementedError
-            If the running platform is a Python version earlier than 3.8
-
-        Notes
-        -----
-        `week` can have the value of 53, only when year is a leap year.
-        """
-        import pandas.compat as compat
-
-        if not compat.PY38:
-            raise NotImplementedError(
-                "'fromisocalendar' is not supported for versions earlier than 3.8"
-            )
-
-        return cls(datetime.fromisocalendar(year, week, day))
-
     def __new__(
         cls,
         object ts_input=_no_input,

pandas/tests/scalar/test_nat.py

@@ -123,6 +123,7 @@ def test_round_nat(klass, method, freq):
         "dst",
         "fromordinal",
         "fromtimestamp",
+        "fromisocalendar",
         "isocalendar",
         "strftime",
         "strptime",
@@ -298,6 +299,10 @@ def test_overlap_public_nat_methods(klass, expected):
     if klass is Timestamp and not compat.PY37:
         expected.remove("fromisoformat")
 
+    # "fromisocalendar" was introduced in 3.8
+    if klass is Timestamp and not compat.PY38:
+        expected.remove("fromisocalendar")
+
     assert _get_overlap_public_nat_methods(klass) == expected