DEPR: rename BQ to BQE for offsets

doc/source/user_guide/timeseries.rst

@@ -886,7 +886,7 @@ into ``freq`` keyword arguments. The available date offsets and associated frequ
     :class:`~pandas.tseries.offsets.SemiMonthBegin`, ``'SMS'``, "15th (or other day_of_month) and calendar month begin"
     :class:`~pandas.tseries.offsets.QuarterEnd`, ``'QE'``, "calendar quarter end"
     :class:`~pandas.tseries.offsets.QuarterBegin`, ``'QS'``, "calendar quarter begin"
-    :class:`~pandas.tseries.offsets.BQuarterEnd`, ``'BQ``, "business quarter end"
+    :class:`~pandas.tseries.offsets.BQuarterEnd`, ``'BQE``, "business quarter end"
     :class:`~pandas.tseries.offsets.BQuarterBegin`, ``'BQS'``, "business quarter begin"
     :class:`~pandas.tseries.offsets.FY5253Quarter`, ``'REQ'``, "retail (aka 52-53 week) quarter"
     :class:`~pandas.tseries.offsets.YearEnd`, ``'YE'``, "calendar year end"
@@ -1249,7 +1249,7 @@ frequencies. We will refer to these aliases as *offset aliases*.
     "BMS", "business month start frequency"
     "CBMS", "custom business month start frequency"
     "QE", "quarter end frequency"
-    "BQ", "business quarter end frequency"
+    "BQE", "business quarter end frequency"
     "QS", "quarter start frequency"
     "BQS", "business quarter start frequency"
     "YE", "year end frequency"
@@ -1686,7 +1686,7 @@ the end of the interval.
 .. warning::
 
     The default values for ``label`` and ``closed`` is '**left**' for all
-    frequency offsets except for 'ME', 'YE', 'QE', 'BME', 'BY', 'BQ', and 'W'
+    frequency offsets except for 'ME', 'YE', 'QE', 'BME', 'BY', 'BQE', and 'W'
     which all have a default of 'right'.
 
     This might unintendedly lead to looking ahead, where the value for a later

doc/source/whatsnew/v2.2.0.rst

@@ -287,6 +287,7 @@ Other Deprecations
 - Deprecated string ``A`` denoting frequency in :class:`YearEnd` and strings ``A-DEC``, ``A-JAN``, etc. denoting annual frequencies with various fiscal year ends (:issue:`54275`)
 - Deprecated string ``BAS`` denoting frequency in :class:`BYearBegin` and strings ``BAS-DEC``, ``BAS-JAN``, etc. denoting annual frequencies with various fiscal year starts (:issue:`54275`)
 - Deprecated string ``BA`` denoting frequency in :class:`BYearEnd` and strings ``BA-DEC``, ``BA-JAN``, etc. denoting annual frequencies with various fiscal year ends (:issue:`54275`)
+- Deprecated string ``BQ`` denoting frequency in :class:`BQuarterEnd` (:issue:`52064`)
 - Deprecated strings ``BM``, and ``CBM`` denoting frequencies in :class:`BusinessMonthEnd`, :class:`CustomBusinessMonthEnd` (:issue:`52064`)
 - Deprecated strings ``H``, ``BH``, and ``CBH`` denoting frequencies in :class:`Hour`, :class:`BusinessHour`, :class:`CustomBusinessHour` (:issue:`52536`)
 - Deprecated strings ``H``, ``S``, ``U``, and ``N`` denoting units in :func:`to_timedelta` (:issue:`52536`)

pandas/_libs/tslibs/dtypes.pyx

@@ -191,7 +191,19 @@ OFFSET_TO_PERIOD_FREQSTR: dict = {
     "BME": "M",
     "BQS": "Q",
     "QS": "Q",
-    "BQ": "Q",
+    "BQE": "Q",
+    "BQE-DEC": "Q-DEC",
+    "BQE-JAN": "Q-JAN",
+    "BQE-FEB": "Q-FEB",
+    "BQE-MAR": "Q-MAR",
+    "BQE-APR": "Q-APR",
+    "BQE-MAY": "Q-MAY",
+    "BQE-JUN": "Q-JUN",
+    "BQE-JUL": "Q-JUL",
+    "BQE-AUG": "Q-AUG",
+    "BQE-SEP": "Q-SEP",
+    "BQE-OCT": "Q-OCT",
+    "BQE-NOV": "Q-NOV",
     "MS": "M",
     "D": "D",
     "B": "B",
@@ -275,6 +287,21 @@ OFFSET_DEPR_FREQSTR: dict[str, str]= {
     "A-SEP": "YE-SEP",
     "A-OCT": "YE-OCT",
     "A-NOV": "YE-NOV",
+    "BM": "BME",
+    "CBM": "CBME",
+    "BQ": "BQE",
+    "BQ-DEC": "BQE-DEC",
+    "BQ-JAN": "BQE-JAN",
+    "BQ-FEB": "BQE-FEB",
+    "BQ-MAR": "BQE-MAR",
+    "BQ-APR": "BQE-APR",
+    "BQ-MAY": "BQE-MAY",
+    "BQ-JUN": "BQE-JUN",
+    "BQ-JUL": "BQE-JUL",
+    "BQ-AUG": "BQE-AUG",
+    "BQ-SEP": "BQE-SEP",
+    "BQ-OCT": "BQE-OCT",
+    "BQ-NOV": "BQE-NOV",
 }
 cdef dict c_OFFSET_TO_PERIOD_FREQSTR = OFFSET_TO_PERIOD_FREQSTR
 cdef dict c_OFFSET_DEPR_FREQSTR = OFFSET_DEPR_FREQSTR

pandas/_libs/tslibs/offsets.pyx

@@ -2693,7 +2693,7 @@ cdef class BQuarterEnd(QuarterOffset):
     _output_name = "BusinessQuarterEnd"
     _default_starting_month = 3
     _from_name_starting_month = 12
-    _prefix = "BQ"
+    _prefix = "BQE"
     _day_opt = "business_end"
 
 
@@ -4568,7 +4568,7 @@ prefix_mapping = {
         BusinessDay,  # 'B'
         BusinessMonthBegin,  # 'BMS'
         BusinessMonthEnd,  # 'BME'
-        BQuarterEnd,  # 'BQ'
+        BQuarterEnd,  # 'BQE'
         BQuarterBegin,  # 'BQS'
         BusinessHour,  # 'bh'
         CustomBusinessDay,  # 'C'
@@ -4752,7 +4752,7 @@ cpdef to_offset(freq, bint is_period=False):
             for n, (sep, stride, name) in enumerate(tups):
                 if is_period is False and name in c_OFFSET_DEPR_FREQSTR:
                     warnings.warn(
-                        f"\'{name}\' will be deprecated, please use "
+                        f"\'{name}\' is deprecated, please use "
                         f"\'{c_OFFSET_DEPR_FREQSTR.get(name)}\' instead.",
                         FutureWarning,
                         stacklevel=find_stack_level(),

pandas/core/generic.py

@@ -9200,11 +9200,11 @@ def resample(
         closed : {{'right', 'left'}}, default None
             Which side of bin interval is closed. The default is 'left'
             for all frequency offsets except for 'ME', 'YE', 'QE', 'BME',
-            'BA', 'BQ', and 'W' which all have a default of 'right'.
+            'BA', 'BQE', and 'W' which all have a default of 'right'.
         label : {{'right', 'left'}}, default None
             Which bin edge label to label bucket with. The default is 'left'
             for all frequency offsets except for 'ME', 'YE', 'QE', 'BME',
-            'BA', 'BQ', and 'W' which all have a default of 'right'.
+            'BA', 'BQE', and 'W' which all have a default of 'right'.
         convention : {{'start', 'end', 's', 'e'}}, default 'start'
             For `PeriodIndex` only, controls whether to use the start or
             end of `rule`.

pandas/core/resample.py

@@ -2130,7 +2130,7 @@ def __init__(
         else:
             freq = to_offset(freq)
 
-        end_types = {"ME", "YE", "QE", "BME", "BY", "BQ", "W"}
+        end_types = {"ME", "YE", "QE", "BME", "BY", "BQE", "W"}
         rule = freq.rule_code
         if rule in end_types or ("-" in rule and rule[: rule.find("-")] in end_types):
             if closed is None:
@@ -2327,7 +2327,7 @@ def _adjust_bin_edges(
         # Some hacks for > daily data, see #1471, #1458, #1483
 
         if self.freq.name in ("BME", "ME", "W") or self.freq.name.split("-")[0] in (
-            "BQ",
+            "BQE",
             "BY",
             "QE",
             "YE",

pandas/tests/arrays/test_datetimes.py

@@ -756,9 +756,7 @@ def test_iter_zoneinfo_fold(self, tz):
     )
     def test_date_range_frequency_M_Q_Y_A_deprecated(self, freq, freq_depr):
         # GH#9586, GH#54275
-        depr_msg = (
-            f"'{freq_depr[1:]}' will be deprecated, please use '{freq[1:]}' instead."
-        )
+        depr_msg = f"'{freq_depr[1:]}' is deprecated, please use '{freq[1:]}' instead."
 
         expected = pd.date_range("1/1/2000", periods=4, freq=freq)
         with tm.assert_produces_warning(FutureWarning, match=depr_msg):

pandas/tests/frame/methods/test_asfreq.py

@@ -240,17 +240,17 @@ def test_asfreq_2ME(self, freq, freq_half):
             ("2ME", "2M"),
             ("2QE", "2Q"),
             ("2QE-SEP", "2Q-SEP"),
+            ("1BQE", "1BQ"),
+            ("2BQE-SEP", "2BQ-SEP"),
             ("1YE", "1Y"),
             ("2YE-MAR", "2Y-MAR"),
             ("1YE", "1A"),
             ("2YE-MAR", "2A-MAR"),
         ],
     )
     def test_asfreq_frequency_M_Q_Y_A_deprecated(self, freq, freq_depr):
-        # GH#9586
-        depr_msg = (
-            f"'{freq_depr[1:]}' will be deprecated, please use '{freq[1:]}' instead."
-        )
+        # GH#9586, #55978
+        depr_msg = f"'{freq_depr[1:]}' is deprecated, please use '{freq[1:]}' instead."
 
         index = date_range("1/1/2000", periods=4, freq=f"{freq[1:]}")
         df = DataFrame({"s": Series([0.0, 1.0, 2.0, 3.0], index=index)})

pandas/tests/indexes/datetimes/methods/test_to_period.py

@@ -50,7 +50,7 @@ def test_to_period_quarterly(self, month):
         result = stamps.to_period(freq)
         tm.assert_index_equal(rng, result)
 
-    @pytest.mark.parametrize("off", ["BQ", "QS", "BQS"])
+    @pytest.mark.parametrize("off", ["BQE", "QS", "BQS"])
     def test_to_period_quarterlyish(self, off):
         rng = date_range("01-Jan-2012", periods=8, freq=off)
         prng = rng.to_period()
@@ -103,7 +103,7 @@ def test_dti_to_period_2monthish(self, freq_offset, freq_period):
     )
     def test_to_period_frequency_M_Q_Y_A_deprecated(self, freq, freq_depr):
         # GH#9586
-        msg = f"'{freq_depr[1:]}' will be deprecated, please use '{freq[1:]}' instead."
+        msg = f"'{freq_depr[1:]}' is deprecated, please use '{freq[1:]}' instead."
 
         rng = date_range("01-Jan-2012", periods=8, freq=freq)
         prng = rng.to_period()

pandas/tests/indexes/datetimes/test_date_range.py

@@ -146,7 +146,7 @@ def test_date_range_float_periods(self):
         tm.assert_index_equal(rng, exp)
 
     def test_date_range_frequency_M_deprecated(self):
-        depr_msg = "'M' will be deprecated, please use 'ME' instead."
+        depr_msg = "'M' is deprecated, please use 'ME' instead."
 
         expected = date_range("1/1/2000", periods=4, freq="2ME")
         with tm.assert_produces_warning(FutureWarning, match=depr_msg):
@@ -786,7 +786,7 @@ def test_frequencies_A_deprecated_Y_renamed(self, freq, freq_depr):
         # GH#9586, GH#54275
         freq_msg = re.split("[0-9]*", freq, maxsplit=1)[1]
         freq_depr_msg = re.split("[0-9]*", freq_depr, maxsplit=1)[1]
-        msg = f"'{freq_depr_msg}' will be deprecated, please use '{freq_msg}' instead."
+        msg = f"'{freq_depr_msg}' is deprecated, please use '{freq_msg}' instead."
 
         expected = date_range("1/1/2000", periods=2, freq=freq)
         with tm.assert_produces_warning(FutureWarning, match=msg):
@@ -1645,7 +1645,7 @@ def test_date_range_fy5253(self, unit):
         "freqstr,offset",
         [
             ("QS", offsets.QuarterBegin(startingMonth=1)),
-            ("BQ", offsets.BQuarterEnd(startingMonth=12)),
+            ("BQE", offsets.BQuarterEnd(startingMonth=12)),
             ("W-SUN", offsets.Week(weekday=6)),
         ],
     )

pandas/tests/indexes/datetimes/test_datetime.py

@@ -201,16 +201,24 @@ def test_AS_BA_BAS_deprecated(self, freq_depr, expected_values, expected_freq):
 
         tm.assert_index_equal(result, expected)
 
-    def test_BM_deprecated(self):
+    @pytest.mark.parametrize(
+        "freq, expected_values, freq_depr",
+        [
+            ("2BME", ["2016-02-29", "2016-04-29", "2016-06-30"], "2BM"),
+            ("2BQE", ["2016-03-31"], "2BQ"),
+            ("1BQE-MAR", ["2016-03-31", "2016-06-30"], "1BQ-MAR"),
+        ],
+    )
+    def test_BM_BQ_deprecated(self, freq, expected_values, freq_depr):
         # GH#52064
-        msg = "'BM' is deprecated and will be removed in a future version."
+        msg = f"'{freq_depr[1:]}' is deprecated, please use '{freq[1:]}' instead."
 
         with tm.assert_produces_warning(FutureWarning, match=msg):
-            expected = date_range(start="2016-02-21", end="2016-08-21", freq="2BM")
+            expected = date_range(start="2016-02-21", end="2016-08-21", freq=freq_depr)
         result = DatetimeIndex(
-            ["2016-02-29", "2016-04-29", "2016-06-30"],
+            data=expected_values,
             dtype="datetime64[ns]",
-            freq="2BME",
+            freq=freq,
         )
 
         tm.assert_index_equal(result, expected)

pandas/tests/indexes/datetimes/test_scalar_compat.py

@@ -308,7 +308,7 @@ def test_dti_fields(self, tz):
         tm.assert_index_equal(res, exp)
 
     def test_dti_is_year_quarter_start(self):
-        dti = date_range(freq="BQ-FEB", start=datetime(1998, 1, 1), periods=4)
+        dti = date_range(freq="BQE-FEB", start=datetime(1998, 1, 1), periods=4)
 
         assert sum(dti.is_quarter_start) == 0
         assert sum(dti.is_quarter_end) == 4

pandas/tests/indexes/period/test_period.py

@@ -299,7 +299,7 @@ def test_a_deprecated_from_time_series(self, freq_depr):
         series = Series(1, index=index)
         assert isinstance(series, Series)
 
-    @pytest.mark.parametrize("freq_depr", ["2ME", "2QE", "2YE"])
+    @pytest.mark.parametrize("freq_depr", ["2ME", "2QE", "2BQE", "2YE"])
     def test_period_index_frequency_error_message(self, freq_depr):
         # GH#9586
         msg = f"for Period, please use '{freq_depr[1:-1]}' "

pandas/tests/resample/test_datetime_index.py

@@ -2058,7 +2058,7 @@ def test_resample_empty_series_with_tz():
 )
 def test_resample_M_Q_Y_A_deprecated(freq, freq_depr):
     # GH#9586
-    depr_msg = f"'{freq_depr[1:]}' will be deprecated, please use '{freq[1:]}' instead."
+    depr_msg = f"'{freq_depr[1:]}' is deprecated, please use '{freq[1:]}' instead."
 
     s = Series(range(10), index=date_range("20130101", freq="d", periods=10))
     expected = s.resample(freq).mean()
@@ -2067,14 +2067,22 @@ def test_resample_M_Q_Y_A_deprecated(freq, freq_depr):
     tm.assert_series_equal(result, expected)
 
 
-def test_resample_BM_deprecated():
+@pytest.mark.parametrize(
+    "freq, freq_depr",
+    [
+        ("2BME", "2BM"),
+        ("2BQE", "2BQ"),
+        ("2BQE-MAR", "2BQ-MAR"),
+    ],
+)
+def test_resample_BM_BQ_deprecated(freq, freq_depr):
     # GH#52064
-    depr_msg = "'BM' is deprecated and will be removed in a future version."
+    depr_msg = f"'{freq_depr[1:]}' is deprecated, please use '{freq[1:]}' instead."
 
     s = Series(range(10), index=date_range("20130101", freq="d", periods=10))
-    expected = s.resample("2BME").mean()
+    expected = s.resample(freq).mean()
     with tm.assert_produces_warning(FutureWarning, match=depr_msg):
-        result = s.resample("2BM").mean()
+        result = s.resample(freq_depr).mean()
     tm.assert_series_equal(result, expected)
 
 

pandas/tests/resample/test_period_index.py

@@ -924,10 +924,13 @@ def test_resample_t_l_deprecated(self):
         tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("freq_depr", ["2ME", "2QE", "2QE-FEB", "2YE", "2YE-MAR"])
+@pytest.mark.parametrize(
+    "freq_depr", ["2ME", "2QE", "2QE-FEB", "2BQE", "2BQE-FEB", "2YE", "2YE-MAR"]
+)
 def test_resample_frequency_ME_QE_error_message(series_and_frame, freq_depr):
     # GH#9586
-    msg = f"for Period, please use '{freq_depr[1:2]}{freq_depr[3:]}' "
+    pos_e = freq_depr.index("E")
+    msg = f"for Period, please use '{freq_depr[1:pos_e]}{freq_depr[pos_e+1:]}' "
     f"instead of '{freq_depr[1:]}'"
 
     obj = series_and_frame

pandas/tests/tseries/offsets/test_offsets.py

@@ -838,7 +838,7 @@ def test_rule_code(self):
             "NOV",
             "DEC",
         ]
-        base_lst = ["YE", "YS", "BY", "BYS", "QE", "QS", "BQ", "BQS"]
+        base_lst = ["YE", "YS", "BY", "BYS", "QE", "QS", "BQE", "BQS"]
         for base in base_lst:
             for v in suffix_lst:
                 alias = "-".join([base, v])
@@ -857,7 +857,7 @@ def test_freq_offsets():
 class TestReprNames:
     def test_str_for_named_is_name(self):
         # look at all the amazing combinations!
-        month_prefixes = ["YE", "YS", "BY", "BYS", "QE", "BQ", "BQS", "QS"]
+        month_prefixes = ["YE", "YS", "BY", "BYS", "QE", "BQE", "BQS", "QS"]
         names = [
             prefix + "-" + month
             for prefix in month_prefixes
@@ -1122,7 +1122,7 @@ def test_is_yqm_start_end():
     bm = to_offset("BME")
     qfeb = to_offset("QE-FEB")
     qsfeb = to_offset("QS-FEB")
-    bq = to_offset("BQ")
+    bq = to_offset("BQE")
     bqs_apr = to_offset("BQS-APR")
     as_nov = to_offset("YS-NOV")
 

pandas/tseries/frequencies.py

@@ -59,7 +59,7 @@
 # --------------------------------------------------------------------
 # Offset related functions
 
-_need_suffix = ["QS", "BQ", "BQS", "YS", "BY", "BYS"]
+_need_suffix = ["QS", "BQE", "BQS", "YS", "BY", "BYS"]
 
 for _prefix in _need_suffix:
     for _m in MONTHS:
@@ -359,7 +359,7 @@ def _get_quarterly_rule(self) -> str | None:
         if pos_check is None:
             return None
         else:
-            return {"cs": "QS", "bs": "BQS", "ce": "QE", "be": "BQ"}.get(pos_check)
+            return {"cs": "QS", "bs": "BQS", "ce": "QE", "be": "BQE"}.get(pos_check)
 
     def _get_monthly_rule(self) -> str | None:
         if len(self.mdiffs) > 1: