CLN: remove deprecated strings 'BA', 'BAS', 'AS' denoting frequencies for timeseries (#57793)

* remove BA, BAS-from timeseries freq, fix tests

* remove AS from timeseries freq, add test

* add notes to v3.0.0

* correct def to_offset

Author: natmokval

doc/source/whatsnew/v3.0.0.rst

@@ -203,7 +203,10 @@ Removal of prior version deprecations/changes
 - Enforced deprecation of :meth:`.DataFrameGroupBy.get_group` and :meth:`.SeriesGroupBy.get_group` allowing the ``name`` argument to be a non-tuple when grouping by a list of length 1 (:issue:`54155`)
 - Enforced deprecation of ``axis=None`` acting the same as ``axis=0`` in the DataFrame reductions ``sum``, ``prod``, ``std``, ``var``, and ``sem``, passing ``axis=None`` will now reduce over both axes; this is particularly the case when doing e.g. ``numpy.sum(df)`` (:issue:`21597`)
 - Enforced deprecation of passing a dictionary to :meth:`SeriesGroupBy.agg` (:issue:`52268`)
+- Enforced deprecation of string ``AS`` denoting frequency in :class:`YearBegin` and strings ``AS-DEC``, ``AS-JAN``, etc. denoting annual frequencies with various fiscal year starts (:issue:`57793`)
 - Enforced deprecation of string ``A`` denoting frequency in :class:`YearEnd` and strings ``A-DEC``, ``A-JAN``, etc. denoting annual frequencies with various fiscal year ends (:issue:`57699`)
+- Enforced deprecation of string ``BAS`` denoting frequency in :class:`BYearBegin` and strings ``BAS-DEC``, ``BAS-JAN``, etc. denoting annual frequencies with various fiscal year starts (:issue:`57793`)
+- Enforced deprecation of string ``BA`` denoting frequency in :class:`BYearEnd` and strings ``BA-DEC``, ``BA-JAN``, etc. denoting annual frequencies with various fiscal year ends (:issue:`57793`)
 - Enforced deprecation of the behavior of :func:`concat` when ``len(keys) != len(objs)`` would truncate to the shorter of the two. Now this raises a ``ValueError`` (:issue:`43485`)
 - Enforced silent-downcasting deprecation for :ref:`all relevant methods <whatsnew_220.silent_downcasting>` (:issue:`54710`)
 - In :meth:`DataFrame.stack`, the default value of ``future_stack`` is now ``True``; specifying ``False`` will raise a ``FutureWarning`` (:issue:`55448`)

pandas/_libs/tslibs/dtypes.pyx

@@ -286,19 +286,6 @@ cdef dict c_OFFSET_DEPR_FREQSTR = {
     "BY-SEP": "BYE-SEP",
     "BY-OCT": "BYE-OCT",
     "BY-NOV": "BYE-NOV",
-    "BA": "BYE",
-    "BA-DEC": "BYE-DEC",
-    "BA-JAN": "BYE-JAN",
-    "BA-FEB": "BYE-FEB",
-    "BA-MAR": "BYE-MAR",
-    "BA-APR": "BYE-APR",
-    "BA-MAY": "BYE-MAY",
-    "BA-JUN": "BYE-JUN",
-    "BA-JUL": "BYE-JUL",
-    "BA-AUG": "BYE-AUG",
-    "BA-SEP": "BYE-SEP",
-    "BA-OCT": "BYE-OCT",
-    "BA-NOV": "BYE-NOV",
     "BM": "BME",
     "CBM": "CBME",
     "SM": "SME",
@@ -323,45 +310,6 @@ cdef dict c_REVERSE_OFFSET_DEPR_FREQSTR = {
 
 # Map deprecated resolution abbreviations to correct resolution abbreviations
 cdef dict c_DEPR_ABBREVS = {
-    "BA": "BY",
-    "BA-DEC": "BY-DEC",
-    "BA-JAN": "BY-JAN",
-    "BA-FEB": "BY-FEB",
-    "BA-MAR": "BY-MAR",
-    "BA-APR": "BY-APR",
-    "BA-MAY": "BY-MAY",
-    "BA-JUN": "BY-JUN",
-    "BA-JUL": "BY-JUL",
-    "BA-AUG": "BY-AUG",
-    "BA-SEP": "BY-SEP",
-    "BA-OCT": "BY-OCT",
-    "BA-NOV": "BY-NOV",
-    "AS": "YS",
-    "AS-DEC": "YS-DEC",
-    "AS-JAN": "YS-JAN",
-    "AS-FEB": "YS-FEB",
-    "AS-MAR": "YS-MAR",
-    "AS-APR": "YS-APR",
-    "AS-MAY": "YS-MAY",
-    "AS-JUN": "YS-JUN",
-    "AS-JUL": "YS-JUL",
-    "AS-AUG": "YS-AUG",
-    "AS-SEP": "YS-SEP",
-    "AS-OCT": "YS-OCT",
-    "AS-NOV": "YS-NOV",
-    "BAS": "BYS",
-    "BAS-DEC": "BYS-DEC",
-    "BAS-JAN": "BYS-JAN",
-    "BAS-FEB": "BYS-FEB",
-    "BAS-MAR": "BYS-MAR",
-    "BAS-APR": "BYS-APR",
-    "BAS-MAY": "BYS-MAY",
-    "BAS-JUN": "BYS-JUN",
-    "BAS-JUL": "BYS-JUL",
-    "BAS-AUG": "BYS-AUG",
-    "BAS-SEP": "BYS-SEP",
-    "BAS-OCT": "BYS-OCT",
-    "BAS-NOV": "BYS-NOV",
     "H": "h",
     "BH": "bh",
     "CBH": "cbh",

pandas/tests/frame/methods/test_asfreq.py

@@ -242,10 +242,9 @@ def test_asfreq_2ME(self, freq, freq_half):
             ("2BQE-SEP", "2BQ-SEP"),
             ("1YE", "1Y"),
             ("2YE-MAR", "2Y-MAR"),
-            ("2BYE-MAR", "2BA-MAR"),
         ],
     )
-    def test_asfreq_frequency_M_Q_Y_A_deprecated(self, freq, freq_depr):
+    def test_asfreq_frequency_M_Q_Y_deprecated(self, freq, freq_depr):
         # GH#9586, #55978
         depr_msg = f"'{freq_depr[1:]}' is deprecated and will be removed "
         f"in a future version, please use '{freq[1:]}' instead."
@@ -282,11 +281,18 @@ def test_asfreq_unsupported_freq(self, freq, error_msg):
         with pytest.raises(ValueError, match=error_msg):
             df.asfreq(freq=freq)
 
-    def test_asfreq_frequency_A_raises(self):
-        msg = "Invalid frequency: 2A"
+    @pytest.mark.parametrize(
+        "freq, freq_depr",
+        [
+            ("2YE", "2A"),
+            ("2BYE-MAR", "2BA-MAR"),
+        ],
+    )
+    def test_asfreq_frequency_A_BA_raises(self, freq, freq_depr):
+        msg = f"Invalid frequency: {freq_depr}"
 
-        index = date_range("1/1/2000", periods=4, freq="2ME")
+        index = date_range("1/1/2000", periods=4, freq=freq)
         df = DataFrame({"s": Series([0.0, 1.0, 2.0, 3.0], index=index)})
 
         with pytest.raises(ValueError, match=msg):
-            df.asfreq(freq="2A")
+            df.asfreq(freq=freq_depr)

pandas/tests/indexes/datetimes/test_datetime.py

@@ -1,6 +1,5 @@
 import datetime as dt
 from datetime import date
-import re
 
 import numpy as np
 import pytest
@@ -158,42 +157,9 @@ def test_CBH_deprecated(self):
 
         tm.assert_index_equal(result, expected)
 
-    @pytest.mark.parametrize(
-        "freq_depr, expected_values, expected_freq",
-        [
-            (
-                "AS-AUG",
-                ["2021-08-01", "2022-08-01", "2023-08-01"],
-                "YS-AUG",
-            ),
-            (
-                "1BAS-MAY",
-                ["2021-05-03", "2022-05-02", "2023-05-01"],
-                "1BYS-MAY",
-            ),
-        ],
-    )
-    def test_AS_BAS_deprecated(self, freq_depr, expected_values, expected_freq):
-        # GH#55479
-        freq_msg = re.split("[0-9]*", freq_depr, maxsplit=1)[1]
-        msg = f"'{freq_msg}' is deprecated and will be removed in a future version."
-
-        with tm.assert_produces_warning(FutureWarning, match=msg):
-            expected = date_range(
-                dt.datetime(2020, 12, 1), dt.datetime(2023, 12, 1), freq=freq_depr
-            )
-        result = DatetimeIndex(
-            expected_values,
-            dtype="datetime64[ns]",
-            freq=expected_freq,
-        )
-
-        tm.assert_index_equal(result, expected)
-
     @pytest.mark.parametrize(
         "freq, expected_values, freq_depr",
         [
-            ("2BYE-MAR", ["2016-03-31"], "2BA-MAR"),
             ("2BYE-JUN", ["2016-06-30"], "2BY-JUN"),
             ("2BME", ["2016-02-29", "2016-04-29", "2016-06-30"], "2BM"),
             ("2BQE", ["2016-03-31"], "2BQ"),
@@ -214,3 +180,10 @@ def test_BM_BQ_BY_deprecated(self, freq, expected_values, freq_depr):
         )
 
         tm.assert_index_equal(result, expected)
+
+    @pytest.mark.parametrize("freq", ["2BA-MAR", "1BAS-MAY", "2AS-AUG"])
+    def test_BA_BAS_raises(self, freq):
+        msg = f"Invalid frequency: {freq}"
+
+        with pytest.raises(ValueError, match=msg):
+            date_range(start="2016-02-21", end="2016-08-21", freq=freq)