DEPR: Remove weekday_name (pandas-dev#29831)

* DEPR: Remove weekday_name

* Fix documentation

doc/source/user_guide/timeseries.rst

@@ -772,7 +772,6 @@ There are several time/date properties that one can access from ``Timestamp`` or
     week,"The week ordinal of the year"
     dayofweek,"The number of the day of the week with Monday=0, Sunday=6"
     weekday,"The number of the day of the week with Monday=0, Sunday=6"
-    weekday_name,"The name of the day in a week (ex: Friday)"
     quarter,"Quarter of the date: Jan-Mar = 1, Apr-Jun = 2, etc."
     days_in_month,"The number of days in the month of the datetime"
     is_month_start,"Logical indicating if first day of month (defined by frequency)"
@@ -1591,18 +1590,18 @@ labels.
 
         s = pd.date_range('2000-01-01', '2000-01-05').to_series()
         s.iloc[2] = pd.NaT
-        s.dt.weekday_name
+        s.dt.day_name()
 
         # default: label='left', closed='left'
-        s.resample('B').last().dt.weekday_name
+        s.resample('B').last().dt.day_name()
 
     Notice how the value for Sunday got pulled back to the previous Friday.
     To get the behavior where the value for Sunday is pushed to Monday, use
     instead
 
     .. ipython:: python
 
-        s.resample('B', label='right', closed='right').last().dt.weekday_name
+        s.resample('B', label='right', closed='right').last().dt.day_name()
 
 The ``axis`` parameter can be set to 0 or 1 and allows you to resample the
 specified axis for a ``DataFrame``.

doc/source/whatsnew/v1.0.0.rst

@@ -455,6 +455,7 @@ or ``matplotlib.Axes.plot``. See :ref:`plotting.formatters` for more.
 - Removed previously deprecated keyword "n" from :meth:`DatetimeIndex.shift`, :meth:`TimedeltaIndex.shift`, :meth:`PeriodIndex.shift`, use "periods" instead (:issue:`22458`)
 - Changed the default value for the `raw` argument in :func:`Series.rolling().apply() <pandas.core.window.Rolling.apply>`, :func:`DataFrame.rolling().apply() <pandas.core.window.Rolling.apply>`,
 - :func:`Series.expanding().apply() <pandas.core.window.Expanding.apply>`, and :func:`DataFrame.expanding().apply() <pandas.core.window.Expanding.apply>` to ``False`` (:issue:`20584`)
+- Removed previously deprecated :attr:`Timestamp.weekday_name`, :attr:`DatetimeIndex.weekday_name`, and :attr:`Series.dt.weekday_name` (:issue:`18164`)
 -
 
 .. _whatsnew_1000.performance:

pandas/_libs/tslibs/fields.pyx

@@ -90,7 +90,7 @@ def build_field_sarray(const int64_t[:] dtindex):
 def get_date_name_field(const int64_t[:] dtindex, object field, object locale=None):
     """
     Given a int64-based datetime index, return array of strings of date
-    name based on requested field (e.g. weekday_name)
+    name based on requested field (e.g. day_name)
     """
     cdef:
         Py_ssize_t i, count = len(dtindex)
@@ -100,7 +100,7 @@ def get_date_name_field(const int64_t[:] dtindex, object field, object locale=No
 
     out = np.empty(count, dtype=object)
 
-    if field == 'day_name' or field == 'weekday_name':
+    if field == 'day_name':
         if locale is None:
             names = np.array(DAYS_FULL, dtype=np.object_)
         else:

pandas/_libs/tslibs/nattype.pyx

@@ -364,7 +364,6 @@ class NaTType(_NaT):
     days_in_month = property(fget=lambda self: np.nan)
     daysinmonth = property(fget=lambda self: np.nan)
     dayofweek = property(fget=lambda self: np.nan)
-    weekday_name = property(fget=lambda self: np.nan)
 
     # inject Timedelta properties
     days = property(fget=lambda self: np.nan)

pandas/_libs/tslibs/timestamps.pyx

@@ -638,17 +638,6 @@ timedelta}, default 'raise'
         """
         return self._get_date_name_field('month_name', locale)
 
-    @property
-    def weekday_name(self) -> str:
-        """
-        .. deprecated:: 0.23.0
-            Use ``Timestamp.day_name()`` instead
-        """
-        warnings.warn("`weekday_name` is deprecated and will be removed in a "
-                      "future version. Use `day_name` instead",
-                      FutureWarning)
-        return self.day_name()
-
     @property
     def dayofyear(self):
         """

pandas/core/arrays/datetimes.py

@@ -277,7 +277,7 @@ class DatetimeArray(dtl.DatetimeLikeArrayMixin, dtl.TimelikeOps, dtl.DatelikeOps
         "is_year_end",
         "is_leap_year",
     ]
-    _object_ops = ["weekday_name", "freq", "tz"]
+    _object_ops = ["freq", "tz"]
     _field_ops = [
         "year",
         "month",
@@ -1509,14 +1509,6 @@ def date(self):
     dayofweek = _field_accessor("dayofweek", "dow", _dayofweek_doc)
     weekday = dayofweek
 
-    weekday_name = _field_accessor(
-        "weekday_name",
-        "weekday_name",
-        """
-        The name of day in a week (ex: Friday)\n\n.. deprecated:: 0.23.0
-        """,
-    )
-
     dayofyear = _field_accessor(
         "dayofyear",
         "doy",

pandas/tests/indexes/datetimes/test_misc.py

@@ -200,7 +200,6 @@ def test_datetimeindex_accessors(self):
             assert len(dti.is_quarter_end) == 365
             assert len(dti.is_year_start) == 365
             assert len(dti.is_year_end) == 365
-            assert len(dti.weekday_name) == 365
 
             dti.name = "name"
 
@@ -339,11 +338,8 @@ def test_datetime_name_accessors(self, time_locale):
         ]
         for day, name, eng_name in zip(range(4, 11), expected_days, english_days):
             name = name.capitalize()
-            assert dti.weekday_name[day] == eng_name
             assert dti.day_name(locale=time_locale)[day] == name
             ts = Timestamp(datetime(2016, 4, day))
-            with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
-                assert ts.weekday_name == eng_name
             assert ts.day_name(locale=time_locale) == name
         dti = dti.append(DatetimeIndex([pd.NaT]))
         assert np.isnan(dti.day_name(locale=time_locale)[-1])

pandas/tests/indexes/datetimes/test_scalar_compat.py

@@ -50,18 +50,13 @@ def test_dti_date_out_of_range(self, data):
             "is_quarter_end",
             "is_year_start",
             "is_year_end",
-            "weekday_name",
         ],
     )
     def test_dti_timestamp_fields(self, field):
         # extra fields from DatetimeIndex like quarter and week
         idx = tm.makeDateIndex(100)
         expected = getattr(idx, field)[-1]
-        if field == "weekday_name":
-            with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
-                result = getattr(Timestamp(idx[-1]), field)
-        else:
-            result = getattr(Timestamp(idx[-1]), field)
+        result = getattr(Timestamp(idx[-1]), field)
         assert result == expected
 
     def test_dti_timestamp_freq_fields(self):

pandas/tests/scalar/timestamp/test_timestamp.py

@@ -108,9 +108,7 @@ def check(value, equal):
     )
     def test_names(self, data, time_locale):
         # GH 17354
-        # Test .weekday_name, .day_name(), .month_name
-        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
-            assert data.weekday_name == "Monday"
+        # Test .day_name(), .month_name
         if time_locale is None:
             expected_day = "Monday"
             expected_month = "August"

pandas/tests/series/test_datetime_values.py

@@ -427,7 +427,6 @@ def test_dt_accessor_datetime_name_accessors(self, time_locale):
         ]
         for day, name, eng_name in zip(range(4, 11), expected_days, english_days):
             name = name.capitalize()
-            assert s.dt.weekday_name[day] == eng_name
             assert s.dt.day_name(locale=time_locale)[day] == name
         s = s.append(Series([pd.NaT]))
         assert np.isnan(s.dt.day_name(locale=time_locale).iloc[-1])