REF: move apply_wraps up into liboffstes (#34062)

Author: jbrockmendel

pandas/_libs/tslibs/offsets.pyx

@@ -6,7 +6,7 @@ import warnings
 from cpython.datetime cimport (PyDateTime_IMPORT,
                                PyDateTime_Check,
                                PyDelta_Check,
-                               datetime, timedelta,
+                               datetime, timedelta, date,
                                time as dt_time)
 PyDateTime_IMPORT
 
@@ -29,12 +29,13 @@ from pandas._libs.tslibs.conversion cimport (
     convert_datetime_to_tsobject,
     localize_pydatetime,
 )
-from pandas._libs.tslibs.nattype cimport NPY_NAT
+from pandas._libs.tslibs.nattype cimport NPY_NAT, c_NaT as NaT
 from pandas._libs.tslibs.np_datetime cimport (
     npy_datetimestruct, dtstruct_to_dt64, dt64_to_dtstruct)
 from pandas._libs.tslibs.timezones cimport utc_pytz as UTC
 from pandas._libs.tslibs.tzconversion cimport tz_convert_single
 
+from pandas._libs.tslibs.timestamps import Timestamp
 
 # ---------------------------------------------------------------------
 # Constants
@@ -154,6 +155,64 @@ def apply_index_wraps(func):
     return wrapper
 
 
+def apply_wraps(func):
+    # Note: normally we would use `@functools.wraps(func)`, but this does
+    # not play nicely with cython class methods
+
+    def wrapper(self, other):
+        if other is NaT:
+            return NaT
+        elif isinstance(other, (timedelta, BaseOffset)):
+            # timedelta path
+            return func(self, other)
+        elif isinstance(other, (np.datetime64, datetime, date)):
+            other = Timestamp(other)
+        else:
+            # This will end up returning NotImplemented back in __add__
+            raise ApplyTypeError
+
+        tz = other.tzinfo
+        nano = other.nanosecond
+
+        if self._adjust_dst:
+            other = other.tz_localize(None)
+
+        result = func(self, other)
+
+        result = Timestamp(result)
+        if self._adjust_dst:
+            result = result.tz_localize(tz)
+
+        if self.normalize:
+            result = result.normalize()
+
+        # nanosecond may be deleted depending on offset process
+        if not self.normalize and nano != 0:
+            if result.nanosecond != nano:
+                if result.tz is not None:
+                    # convert to UTC
+                    value = result.tz_localize(None).value
+                else:
+                    value = result.value
+                result = Timestamp(value + nano)
+
+        if tz is not None and result.tzinfo is None:
+            result = result.tz_localize(tz)
+
+        return result
+
+    # do @functools.wraps(func) manually since it doesn't work on cdef funcs
+    wrapper.__name__ = func.__name__
+    wrapper.__doc__ = func.__doc__
+    try:
+        wrapper.__module__ = func.__module__
+    except AttributeError:
+        # AttributeError: 'method_descriptor' object has no
+        # attribute '__module__'
+        pass
+    return wrapper
+
+
 cdef _wrap_timedelta_result(result):
     """
     Tick operations dispatch to their Timedelta counterparts.  Wrap the result
@@ -348,6 +407,10 @@ class _BaseOffset:
     _typ = "dateoffset"
     _day_opt = None
     _attributes = frozenset(['n', 'normalize'])
+    _use_relativedelta = False
+    _adjust_dst = False
+    _deprecations = frozenset(["isAnchored", "onOffset"])
+    normalize = False  # default for prior pickles
 
     def __init__(self, n=1, normalize=False):
         n = self._validate_n(n)
@@ -503,11 +566,41 @@ class _BaseOffset:
 
     # ------------------------------------------------------------------
 
+    def rollback(self, dt):
+        """
+        Roll provided date backward to next offset only if not on offset.
+
+        Returns
+        -------
+        TimeStamp
+            Rolled timestamp if not on offset, otherwise unchanged timestamp.
+        """
+        dt = Timestamp(dt)
+        if not self.is_on_offset(dt):
+            dt = dt - type(self)(1, normalize=self.normalize, **self.kwds)
+        return dt
+
+    def rollforward(self, dt):
+        """
+        Roll provided date forward to next offset only if not on offset.
+
+        Returns
+        -------
+        TimeStamp
+            Rolled timestamp if not on offset, otherwise unchanged timestamp.
+        """
+        dt = Timestamp(dt)
+        if not self.is_on_offset(dt):
+            dt = dt + type(self)(1, normalize=self.normalize, **self.kwds)
+        return dt
+
     def _get_offset_day(self, datetime other):
         # subclass must implement `_day_opt`; calling from the base class
         # will raise NotImplementedError.
         return get_day_of_month(other, self._day_opt)
 
+    # ------------------------------------------------------------------
+
     def _validate_n(self, n):
         """
         Require that `n` be an integer.
@@ -620,6 +713,12 @@ cdef class _Tick(ABCTick):
     # ensure that reversed-ops with numpy scalars return NotImplemented
     __array_priority__ = 1000
 
+    def is_on_offset(self, dt) -> bool:
+        return True
+
+    def is_anchored(self) -> bool:
+        return False
+
     def __truediv__(self, other):
         if not isinstance(self, _Tick):
             # cython semantics mean the args are sometimes swapped

pandas/_libs/tslibs/timedeltas.pyx

@@ -31,7 +31,6 @@ from pandas._libs.tslibs.np_datetime cimport (
 from pandas._libs.tslibs.nattype import nat_strings
 from pandas._libs.tslibs.nattype cimport (
     checknull_with_nat, NPY_NAT, c_NaT as NaT)
-from pandas._libs.tslibs.offsets cimport to_offset
 
 # ----------------------------------------------------------------------
 # Constants
@@ -1273,6 +1272,7 @@ class Timedelta(_Timedelta):
         cdef:
             int64_t result, unit
 
+        from pandas.tseries.frequencies import to_offset
         unit = to_offset(freq).nanos
         result = unit * rounder(self.value / float(unit))
         return Timedelta(result, unit='ns')

pandas/tseries/offsets.py

@@ -1,5 +1,4 @@
 from datetime import date, datetime, timedelta
-import functools
 import operator
 from typing import Any, Optional
 
@@ -23,6 +22,7 @@
     BusinessMixin,
     CustomMixin,
     apply_index_wraps,
+    apply_wraps,
     as_datetime,
     is_normalized,
     roll_yearday,
@@ -74,53 +74,6 @@
 ]
 
 
-def apply_wraps(func):
-    @functools.wraps(func)
-    def wrapper(self, other):
-        if other is NaT:
-            return NaT
-        elif isinstance(other, (timedelta, DateOffset)):
-            # timedelta path
-            return func(self, other)
-        elif isinstance(other, (np.datetime64, datetime, date)):
-            other = Timestamp(other)
-        else:
-            # This will end up returning NotImplemented back in __add__
-            raise ApplyTypeError
-
-        tz = other.tzinfo
-        nano = other.nanosecond
-
-        if self._adjust_dst:
-            other = other.tz_localize(None)
-
-        result = func(self, other)
-
-        result = Timestamp(result)
-        if self._adjust_dst:
-            result = result.tz_localize(tz)
-
-        if self.normalize:
-            result = result.normalize()
-
-        # nanosecond may be deleted depending on offset process
-        if not self.normalize and nano != 0:
-            if not isinstance(self, Nano) and result.nanosecond != nano:
-                if result.tz is not None:
-                    # convert to UTC
-                    value = result.tz_localize(None).value
-                else:
-                    value = result.value
-                result = Timestamp(value + nano)
-
-        if tz is not None and result.tzinfo is None:
-            result = result.tz_localize(tz)
-
-        return result
-
-    return wrapper
-
-
 # ---------------------------------------------------------------------
 # DateOffset
 
@@ -222,13 +175,7 @@ def __add__(date):
 
     _params = cache_readonly(BaseOffset._params.fget)
     freqstr = cache_readonly(BaseOffset.freqstr.fget)
-    _use_relativedelta = False
-    _adjust_dst = False
     _attributes = frozenset(["n", "normalize"] + list(liboffsets.relativedelta_kwds))
-    _deprecations = frozenset(["isAnchored", "onOffset"])
-
-    # default for prior pickles
-    normalize = False
 
     def __init__(self, n=1, normalize=False, **kwds):
         BaseOffset.__init__(self, n, normalize)
@@ -357,39 +304,11 @@ def _repr_attrs(self) -> str:
             out += ": " + ", ".join(attrs)
         return out
 
-    def rollback(self, dt):
-        """
-        Roll provided date backward to next offset only if not on offset.
-
-        Returns
-        -------
-        TimeStamp
-            Rolled timestamp if not on offset, otherwise unchanged timestamp.
-        """
-        dt = Timestamp(dt)
-        if not self.is_on_offset(dt):
-            dt = dt - type(self)(1, normalize=self.normalize, **self.kwds)
-        return dt
-
-    def rollforward(self, dt):
-        """
-        Roll provided date forward to next offset only if not on offset.
-
-        Returns
-        -------
-        TimeStamp
-            Rolled timestamp if not on offset, otherwise unchanged timestamp.
-        """
-        dt = Timestamp(dt)
-        if not self.is_on_offset(dt):
-            dt = dt + type(self)(1, normalize=self.normalize, **self.kwds)
-        return dt
-
     def is_on_offset(self, dt):
         if self.normalize and not is_normalized(dt):
             return False
         # TODO, see #1395
-        if type(self) == DateOffset or isinstance(self, Tick):
+        if type(self) is DateOffset:
             return True
 
         # Default (slow) method for determining if some date is a member of the
@@ -2486,9 +2405,6 @@ def apply(self, other):
 
         raise ApplyTypeError(f"Unhandled type: {type(other).__name__}")
 
-    def is_anchored(self) -> bool:
-        return False
-
 
 def delta_to_tick(delta: timedelta) -> Tick:
     if delta.microseconds == 0 and getattr(delta, "nanoseconds", 0) == 0: