ENH: add basic fold support

Author: AlexKirko

pandas/_libs/tslib.pyx

@@ -49,30 +49,30 @@ from pandas._libs.tslibs.tzconversion cimport (
 
 cdef inline object create_datetime_from_ts(
         int64_t value, npy_datetimestruct dts,
-        object tz, object freq):
+        object tz, object freq, bint fold):
     """ convenience routine to construct a datetime.datetime from its parts """
     return datetime(dts.year, dts.month, dts.day, dts.hour,
                     dts.min, dts.sec, dts.us, tz)
 
 
 cdef inline object create_date_from_ts(
         int64_t value, npy_datetimestruct dts,
-        object tz, object freq):
+        object tz, object freq, bint fold):
     """ convenience routine to construct a datetime.date from its parts """
     return date(dts.year, dts.month, dts.day)
 
 
 cdef inline object create_time_from_ts(
         int64_t value, npy_datetimestruct dts,
-        object tz, object freq):
+        object tz, object freq, bint fold):
     """ convenience routine to construct a datetime.time from its parts """
     return time(dts.hour, dts.min, dts.sec, dts.us, tz)
 
 
 @cython.wraparound(False)
 @cython.boundscheck(False)
 def ints_to_pydatetime(const int64_t[:] arr, object tz=None, object freq=None,
-                       str box="datetime"):
+                       bint fold=0, str box="datetime"):
     """
     Convert an i8 repr to an ndarray of datetimes, date, time or Timestamp
 
@@ -104,7 +104,7 @@ def ints_to_pydatetime(const int64_t[:] arr, object tz=None, object freq=None,
         str typ
         int64_t value, delta, local_value
         ndarray[object] result = np.empty(n, dtype=object)
-        object (*func_create)(int64_t, npy_datetimestruct, object, object)
+        object (*func_create)(int64_t, npy_datetimestruct, object, object, bint)
 
     if box == "date":
         assert (tz is None), "tz should be None when converting to date"
@@ -129,7 +129,7 @@ def ints_to_pydatetime(const int64_t[:] arr, object tz=None, object freq=None,
                 result[i] = <object>NaT
             else:
                 dt64_to_dtstruct(value, &dts)
-                result[i] = func_create(value, dts, tz, freq)
+                result[i] = func_create(value, dts, tz, freq, fold)
     elif is_tzlocal(tz):
         for i in range(n):
             value = arr[i]
@@ -141,7 +141,7 @@ def ints_to_pydatetime(const int64_t[:] arr, object tz=None, object freq=None,
                 # using the i8 representation.
                 local_value = tz_convert_utc_to_tzlocal(value, tz)
                 dt64_to_dtstruct(local_value, &dts)
-                result[i] = func_create(value, dts, tz, freq)
+                result[i] = func_create(value, dts, tz, freq, fold)
     else:
         trans, deltas, typ = get_dst_info(tz)
 
@@ -155,7 +155,7 @@ def ints_to_pydatetime(const int64_t[:] arr, object tz=None, object freq=None,
                 else:
                     # Adjust datetime64 timestamp, recompute datetimestruct
                     dt64_to_dtstruct(value + delta, &dts)
-                    result[i] = func_create(value, dts, tz, freq)
+                    result[i] = func_create(value, dts, tz, freq, fold)
 
         elif typ == 'dateutil':
             # no zone-name change for dateutil tzs - dst etc
@@ -168,7 +168,7 @@ def ints_to_pydatetime(const int64_t[:] arr, object tz=None, object freq=None,
                     # Adjust datetime64 timestamp, recompute datetimestruct
                     pos = trans.searchsorted(value, side='right') - 1
                     dt64_to_dtstruct(value + deltas[pos], &dts)
-                    result[i] = func_create(value, dts, tz, freq)
+                    result[i] = func_create(value, dts, tz, freq, fold)
         else:
             # pytz
             for i in range(n):
@@ -182,7 +182,7 @@ def ints_to_pydatetime(const int64_t[:] arr, object tz=None, object freq=None,
                     new_tz = tz._tzinfos[tz._transition_info[pos]]
 
                     dt64_to_dtstruct(value + deltas[pos], &dts)
-                    result[i] = func_create(value, dts, new_tz, freq)
+                    result[i] = func_create(value, dts, new_tz, freq, fold)
 
     return result
 

pandas/_libs/tslibs/timestamps.pxd

@@ -5,4 +5,4 @@ from pandas._libs.tslibs.np_datetime cimport npy_datetimestruct
 
 cdef object create_timestamp_from_ts(int64_t value,
                                      npy_datetimestruct dts,
-                                     object tz, object freq)
+                                     object tz, object freq, bint fold)

pandas/_libs/tslibs/timestamps.pyx

@@ -42,12 +42,12 @@ _no_input = object()
 
 cdef inline object create_timestamp_from_ts(int64_t value,
                                             npy_datetimestruct dts,
-                                            object tz, object freq):
+                                            object tz, object freq, bint fold):
     """ convenience routine to construct a Timestamp from its parts """
     cdef _Timestamp ts_base
     ts_base = _Timestamp.__new__(Timestamp, dts.year, dts.month,
                                  dts.day, dts.hour, dts.min,
-                                 dts.sec, dts.us, tz)
+                                 dts.sec, dts.us, tz, fold=fold)
     ts_base.value = value
     ts_base.freq = freq
     ts_base.nanosecond = dts.ps // 1000
@@ -442,7 +442,7 @@ class Timestamp(_Timestamp):
         elif not is_offset_object(freq):
             freq = to_offset(freq)
 
-        return create_timestamp_from_ts(ts.value, ts.dts, ts.tzinfo, freq)
+        return create_timestamp_from_ts(ts.value, ts.dts, ts.tzinfo, freq, fold)
 
     def _round(self, freq, mode, ambiguous='raise', nonexistent='raise'):
         if self.tz is not None:
@@ -986,7 +986,7 @@ default 'raise'
         if value != NPY_NAT:
             check_dts_bounds(&dts)
 
-        return create_timestamp_from_ts(value, dts, _tzinfo, self.freq)
+        return create_timestamp_from_ts(value, dts, _tzinfo, self.freq, fold)
 
     def isoformat(self, sep='T'):
         base = super(_Timestamp, self).isoformat(sep=sep)