REF: inherit BaseOffset in BusinessMixin

pandas/_libs/tslibs/offsets.pyx

@@ -788,10 +788,13 @@ cdef class _Tick(ABCTick):
         object.__setattr__(self, "n", state["n"])
 
 
-class BusinessMixin:
+class BusinessMixin(BaseOffset):
     """
     Mixin to business types to provide related functions.
     """
+    def __init__(self, n=1, normalize=False, offset=timedelta(0)):
+        BaseOffset.__init__(self, n, normalize)
+        object.__setattr__(self, "_offset", offset)
 
     @property
     def offset(self):
@@ -815,7 +818,11 @@ class BusinessMixin:
 class BusinessHourMixin(BusinessMixin):
     _adjust_dst = False
 
-    def __init__(self, start="09:00", end="17:00", offset=timedelta(0)):
+    def __init__(
+            self, n=1, normalize=False, start="09:00", end="17:00", offset=timedelta(0)
+        ):
+        BusinessMixin.__init__(self, n, normalize, offset)
+
         # must be validated here to equality check
         if np.ndim(start) == 0:
             # i.e. not is_list_like
@@ -859,7 +866,6 @@ class BusinessHourMixin(BusinessMixin):
 
         object.__setattr__(self, "start", start)
         object.__setattr__(self, "end", end)
-        object.__setattr__(self, "_offset", offset)
 
     def _repr_attrs(self) -> str:
         out = super()._repr_attrs()

pandas/tseries/frequencies.py

@@ -165,7 +165,7 @@ def to_offset(freq) -> Optional[DateOffset]:
                     )
                 stride = int(stride)
                 offset = _get_offset(name)
-                offset = offset * int(np.fabs(stride) * stride_sign)
+                offset = offset * int(np.fabs(stride) * stride_sign)  # type: ignore
                 if delta is None:
                     delta = offset
                 else:

pandas/tseries/offsets.py

@@ -296,7 +296,7 @@ def is_on_offset(self, dt):
         return True
 
 
-class SingleConstructorOffset(BaseOffset):
+class SingleConstructorMixin:
     _params = cache_readonly(BaseOffset._params.fget)
     freqstr = cache_readonly(BaseOffset.freqstr.fget)
 
@@ -308,6 +308,10 @@ def _from_name(cls, suffix=None):
         return cls()
 
 
+class SingleConstructorOffset(SingleConstructorMixin, BaseOffset):
+    pass
+
+
 class BusinessDay(BusinessMixin, SingleConstructorOffset):
     """
     DateOffset subclass representing possibly n business days.
@@ -316,10 +320,6 @@ class BusinessDay(BusinessMixin, SingleConstructorOffset):
     _prefix = "B"
     _attributes = frozenset(["n", "normalize", "offset"])
 
-    def __init__(self, n=1, normalize=False, offset=timedelta(0)):
-        BaseOffset.__init__(self, n, normalize)
-        object.__setattr__(self, "_offset", offset)
-
     def _offset_str(self) -> str:
         def get_str(td):
             off_str = ""
@@ -419,7 +419,15 @@ def is_on_offset(self, dt: datetime) -> bool:
         return dt.weekday() < 5
 
 
-class BusinessHourMixin(liboffsets.BusinessHourMixin):
+class BusinessHour(SingleConstructorMixin, liboffsets.BusinessHourMixin):
+    """
+    DateOffset subclass representing possibly n business hours.
+    """
+
+    _prefix = "BH"
+    _anchor = 0
+    _attributes = frozenset(["n", "normalize", "start", "end", "offset"])
+
     @cache_readonly
     def next_bday(self):
         """
@@ -679,22 +687,6 @@ def _is_on_offset(self, dt):
             return False
 
 
-class BusinessHour(BusinessHourMixin, SingleConstructorOffset):
-    """
-    DateOffset subclass representing possibly n business hours.
-    """
-
-    _prefix = "BH"
-    _anchor = 0
-    _attributes = frozenset(["n", "normalize", "start", "end", "offset"])
-
-    def __init__(
-        self, n=1, normalize=False, start="09:00", end="17:00", offset=timedelta(0)
-    ):
-        BaseOffset.__init__(self, n, normalize)
-        super().__init__(start=start, end=end, offset=offset)
-
-
 class CustomBusinessDay(CustomMixin, BusinessDay):
     """
     DateOffset subclass representing custom business days excluding holidays.
@@ -727,9 +719,7 @@ def __init__(
         calendar=None,
         offset=timedelta(0),
     ):
-        BaseOffset.__init__(self, n, normalize)
-        object.__setattr__(self, "_offset", offset)
-
+        BusinessDay.__init__(self, n, normalize, offset)
         CustomMixin.__init__(self, weekmask, holidays, calendar)
 
     @apply_wraps
@@ -772,7 +762,7 @@ def is_on_offset(self, dt: datetime) -> bool:
         return np.is_busday(day64, busdaycal=self.calendar)
 
 
-class CustomBusinessHour(CustomMixin, BusinessHourMixin, SingleConstructorOffset):
+class CustomBusinessHour(CustomMixin, BusinessHour):
     """
     DateOffset subclass representing possibly n custom business days.
     """
@@ -794,11 +784,8 @@ def __init__(
         end="17:00",
         offset=timedelta(0),
     ):
-        BaseOffset.__init__(self, n, normalize)
-        object.__setattr__(self, "_offset", offset)
-
+        BusinessHour.__init__(self, n, normalize, start=start, end=end, offset=offset)
         CustomMixin.__init__(self, weekmask, holidays, calendar)
-        BusinessHourMixin.__init__(self, start=start, end=end, offset=offset)
 
 
 # ---------------------------------------------------------------------
@@ -898,9 +885,7 @@ def __init__(
         calendar=None,
         offset=timedelta(0),
     ):
-        BaseOffset.__init__(self, n, normalize)
-        object.__setattr__(self, "_offset", offset)
-
+        BusinessMixin.__init__(self, n, normalize, offset)
         CustomMixin.__init__(self, weekmask, holidays, calendar)
 
     @cache_readonly
@@ -980,9 +965,9 @@ def __init__(self, n=1, normalize=False, day_of_month=None):
         BaseOffset.__init__(self, n, normalize)
 
         if day_of_month is None:
-            object.__setattr__(self, "day_of_month", self._default_day_of_month)
-        else:
-            object.__setattr__(self, "day_of_month", int(day_of_month))
+            day_of_month = self._default_day_of_month
+
+        object.__setattr__(self, "day_of_month", int(day_of_month))
         if not self._min_day_of_month <= self.day_of_month <= 27:
             raise ValueError(
                 "day_of_month must be "