ENH: fields.get_start_end_field support non-nano (#46902)

* ENH: fields.get_start_end_field support non-nano

* fix non-mac builds

Author: jbrockmendel

asv_bench/benchmarks/tslibs/fields.py

@@ -66,9 +66,9 @@ class TimeGetStartEndField:
 
     def setup(self, size, side, period, freqstr, month_kw):
         arr = np.random.randint(0, 10, size=size, dtype="i8")
-        self.i8data = arr
+        self.dt64data = arr.view("M8[ns]")
 
         self.attrname = f"is_{period}_{side}"
 
     def time_get_start_end_field(self, size, side, period, freqstr, month_kw):
-        get_start_end_field(self.i8data, self.attrname, freqstr, month_kw=month_kw)
+        get_start_end_field(self.dt64data, self.attrname, freqstr, month_kw=month_kw)

pandas/_libs/tslibs/fields.pyi

@@ -12,7 +12,7 @@ def get_date_name_field(
     locale: str | None = ...,
 ) -> npt.NDArray[np.object_]: ...
 def get_start_end_field(
-    dtindex: npt.NDArray[np.int64],  # const int64_t[:]
+    dt64values: npt.NDArray[np.datetime64],
     field: str,
     freqstr: str | None = ...,
     month_kw: int = ...,

pandas/_libs/tslibs/fields.pyx

@@ -5,8 +5,10 @@ objects and arrays
 from locale import LC_TIME
 
 from _strptime import LocaleTime
+
 cimport cython
 from cython cimport Py_ssize_t
+
 import numpy as np
 
 cimport numpy as cnp
@@ -41,8 +43,11 @@ from pandas._libs.tslibs.ccalendar cimport (
 )
 from pandas._libs.tslibs.nattype cimport NPY_NAT
 from pandas._libs.tslibs.np_datetime cimport (
+    NPY_DATETIMEUNIT,
     dt64_to_dtstruct,
+    get_unit_from_dtype,
     npy_datetimestruct,
+    pandas_datetime_to_datetimestruct,
     pandas_timedeltastruct,
     td64_to_tdstruct,
 )
@@ -196,22 +201,35 @@ cdef inline bint _is_on_month(int month, int compare_month, int modby) nogil:
 
 @cython.wraparound(False)
 @cython.boundscheck(False)
-def get_start_end_field(const int64_t[:] dtindex, str field,
+def get_start_end_field(ndarray dt64values, str field,
                         str freqstr=None, int month_kw=12):
     """
     Given an int64-based datetime index return array of indicators
     of whether timestamps are at the start/end of the month/quarter/year
     (defined by frequency).
+
+    Parameters
+    ----------
+    dt64values : ndarray[datetime64], any resolution
+    field : str
+    frestr : str or None, default None
+    month_kw : int, default 12
+
+    Returns
+    -------
+    ndarray[bool]
     """
     cdef:
         Py_ssize_t i
-        int count = len(dtindex)
+        int count = dt64values.size
         bint is_business = 0
         int end_month = 12
         int start_month = 1
         ndarray[int8_t] out
         npy_datetimestruct dts
         int compare_month, modby
+        ndarray dtindex = dt64values.view("i8")
+        NPY_DATETIMEUNIT reso = get_unit_from_dtype(dt64values.dtype)
 
     out = np.zeros(count, dtype='int8')
 
@@ -251,7 +269,7 @@ def get_start_end_field(const int64_t[:] dtindex, str field,
                     out[i] = 0
                     continue
 
-                dt64_to_dtstruct(dtindex[i], &dts)
+                pandas_datetime_to_datetimestruct(dtindex[i], reso, &dts)
 
                 if _is_on_month(dts.month, compare_month, modby) and (
                         dts.day == get_firstbday(dts.year, dts.month)):
@@ -263,7 +281,7 @@ def get_start_end_field(const int64_t[:] dtindex, str field,
                     out[i] = 0
                     continue
 
-                dt64_to_dtstruct(dtindex[i], &dts)
+                pandas_datetime_to_datetimestruct(dtindex[i], reso, &dts)
 
                 if _is_on_month(dts.month, compare_month, modby) and dts.day == 1:
                     out[i] = 1
@@ -275,7 +293,7 @@ def get_start_end_field(const int64_t[:] dtindex, str field,
                     out[i] = 0
                     continue
 
-                dt64_to_dtstruct(dtindex[i], &dts)
+                pandas_datetime_to_datetimestruct(dtindex[i], reso, &dts)
 
                 if _is_on_month(dts.month, compare_month, modby) and (
                         dts.day == get_lastbday(dts.year, dts.month)):
@@ -287,7 +305,7 @@ def get_start_end_field(const int64_t[:] dtindex, str field,
                     out[i] = 0
                     continue
 
-                dt64_to_dtstruct(dtindex[i], &dts)
+                pandas_datetime_to_datetimestruct(dtindex[i], reso, &dts)
 
                 if _is_on_month(dts.month, compare_month, modby) and (
                         dts.day == get_days_in_month(dts.year, dts.month)):

pandas/_libs/tslibs/timestamps.pyx

@@ -487,9 +487,7 @@ cdef class _Timestamp(ABCTimestamp):
             dict kwds
             ndarray[uint8_t, cast=True] out
             int month_kw
-
-        if self._reso != NPY_FR_ns:
-            raise NotImplementedError(self._reso)
+            str unit
 
         if freq:
             kwds = freq.kwds
@@ -500,7 +498,9 @@ cdef class _Timestamp(ABCTimestamp):
             freqstr = None
 
         val = self._maybe_convert_value_to_local()
-        out = get_start_end_field(np.array([val], dtype=np.int64),
+
+        unit = npy_unit_to_abbrev(self._reso)
+        out = get_start_end_field(np.array([val], dtype=f"M8[{unit}]"),
                                   field, freqstr, month_kw)
         return out[0]
 

pandas/core/arrays/datetimes.py

@@ -130,7 +130,7 @@ def f(self):
                     month_kw = kwds.get("startingMonth", kwds.get("month", 12))
 
                 result = fields.get_start_end_field(
-                    values, field, self.freqstr, month_kw
+                    values.view(self._ndarray.dtype), field, self.freqstr, month_kw
                 )
             else:
                 result = fields.get_date_field(values, field)

pandas/tests/scalar/timestamp/test_timestamp.py

@@ -732,6 +732,27 @@ def test_non_nano_fields(self, dt64, ts):
         assert ts.weekday() == alt.weekday()
         assert ts.isoweekday() == alt.isoweekday()
 
+    def test_start_end_fields(self, ts):
+        assert ts.is_year_start
+        assert ts.is_quarter_start
+        assert ts.is_month_start
+        assert not ts.is_year_end
+        assert not ts.is_month_end
+        assert not ts.is_month_end
+
+        freq = offsets.BDay()
+        ts._set_freq(freq)
+
+        # 2016-01-01 is a Friday, so is year/quarter/month start with this freq
+        msg = "Timestamp.freq is deprecated"
+        with tm.assert_produces_warning(FutureWarning, match=msg):
+            assert ts.is_year_start
+            assert ts.is_quarter_start
+            assert ts.is_month_start
+            assert not ts.is_year_end
+            assert not ts.is_month_end
+            assert not ts.is_month_end
+
     def test_repr(self, dt64, ts):
         alt = Timestamp(dt64)
 

pandas/tests/tslibs/test_fields.py

@@ -28,7 +28,10 @@ def test_get_date_field_readonly(dtindex):
 
 
 def test_get_start_end_field_readonly(dtindex):
-    result = fields.get_start_end_field(dtindex, "is_month_start", None)
+    dt64values = dtindex.view("M8[ns]")
+    dt64values.flags.writeable = False
+
+    result = fields.get_start_end_field(dt64values, "is_month_start", None)
     expected = np.array([True, False, False, False, False], dtype=np.bool_)
     tm.assert_numpy_array_equal(result, expected)
 

setup.py

@@ -506,6 +506,7 @@ def srcpath(name=None, suffix=".pyx", subdir="src"):
     "_libs.tslibs.fields": {
         "pyxfile": "_libs/tslibs/fields",
         "depends": tseries_depends,
+        "sources": ["pandas/_libs/tslibs/src/datetime/np_datetime.c"],
     },
     "_libs.tslibs.nattype": {"pyxfile": "_libs/tslibs/nattype"},
     "_libs.tslibs.np_datetime": {