docstrings, de-privatize, types

pandas/_libs/tslibs/offsets.pyx

@@ -824,7 +824,23 @@ cpdef int get_day_of_month(datetime other, day_opt) except? -1:
         raise ValueError(day_opt)
 
 
-cpdef int roll_monthday(int n, other, compare):
+cpdef int roll_monthday(other, int n, compare):
+    """
+    Possibly increment or decrement the number of periods to shift
+    based on rollforward/rollbackward conventions.
+
+    Parameters
+    ----------
+    other : datetime or Timestamp
+    n : number of periods to increment, before adjusting for rolling
+    day_opt : 'start', 'end', 'business_start', 'business_end'
+        The convention to use in finding the day in a given month against
+        which to compare for rollforward/rollbackward decisions.
+
+    Returns
+    -------
+    n : int number of periods to increment
+    """
     # Either `other` and `compare` are _both_ datetimes or they are both
     # integers for days in the same month.
 
@@ -836,8 +852,25 @@ cpdef int roll_monthday(int n, other, compare):
     return n
 
 
-cpdef inline int roll_qtrday(other, n, month, day_opt='start',
-                             int modby=3) except? -1:
+cpdef int roll_qtrday(datetime other, int n, int month, day_opt='start',
+                      int modby=3) except? -1:
+    """
+    Possibly increment or decrement the number of periods to shift
+    based on rollforward/rollbackward conventions.
+
+    Parameters
+    ----------
+    other : datetime or Timestamp
+    n : number of periods to increment, before adjusting for rolling
+    month : reference month giving the first month of the year
+    day_opt : 'start', 'end', 'business_start', 'business_end'
+        The convention to use in finding the day in a given month against
+        which to compare for rollforward/rollbackward decisions.
+
+    Returns
+    -------
+    n : int number of periods to increment
+    """
     # TODO: type `other` as datetime-or-pandas_datetimestruct?
     # TODO: Merge this with roll_yearday by setting modby=12 there?
     #       code de-duplication versus perf hit?
@@ -869,6 +902,7 @@ cpdef int roll_yearday(other, n, month, day_opt='start') except? -1:
     ----------
     other : datetime or Timestamp
     n : number of periods to increment, before adjusting for rolling
+    month : reference month giving the first month of the year
     day_opt : 'start', 'end'
         'start': returns 1
         'end': returns last day  of the month

pandas/tseries/offsets.py

@@ -945,7 +945,7 @@ def onOffset(self, dt):
     @apply_wraps
     def apply(self, other):
         compare_day = self._get_offset_day(other)
-        n = liboffsets.roll_monthday(self.n, other.day, compare_day)
+        n = liboffsets.roll_monthday(other.day, self.n, compare_day)
         return shift_month(other, n, self._day_opt)
 
     @apply_index_wraps
@@ -1036,7 +1036,7 @@ def apply(self, other):
 
         # Find this custom month offset
         compare_day = self.cbday.rollback(cur_mend)
-        n = liboffsets.roll_monthday(self.n, other, compare_day)
+        n = liboffsets.roll_monthday(other, self.n, compare_day)
 
         new = cur_mend + n * self.m_offset
         result = self.cbday.rollback(new)
@@ -1054,7 +1054,7 @@ def apply(self, other):
 
         # Find this custom month offset
         compare_day = self.cbday.rollforward(cur_mbegin)
-        n = liboffsets.roll_monthday(self.n, other, compare_day)
+        n = liboffsets.roll_monthday(other, self.n, compare_day)
 
         new = cur_mbegin + n * self.m_offset
         result = self.cbday.rollforward(new)
@@ -1095,7 +1095,7 @@ def rule_code(self):
     @apply_wraps
     def apply(self, other):
         # shift `other` to self.day_of_month, incrementing `n` if necessary
-        n = liboffsets.roll_monthday(self.n, other.day, self.day_of_month)
+        n = liboffsets.roll_monthday(other.day, self.n, self.day_of_month)
 
         days_in_month = tslib.monthrange(other.year, other.month)[1]
 
@@ -1366,7 +1366,7 @@ def apply(self, other):
         base = other
         offsetOfMonth = self.getOffsetOfMonth(other)
 
-        months = liboffsets.roll_monthday(self.n, other, offsetOfMonth)
+        months = liboffsets.roll_monthday(other, self.n, offsetOfMonth)
 
         other = self.getOffsetOfMonth(shift_month(other, months, 'start'))
         other = datetime(other.year, other.month, other.day, base.hour,
@@ -1444,7 +1444,7 @@ def __init__(self, n=1, normalize=False, weekday=None):
     def apply(self, other):
         offsetOfMonth = self.getOffsetOfMonth(other)
 
-        months = liboffsets.roll_monthday(self.n, other, offsetOfMonth)
+        months = liboffsets.roll_monthday(other, self.n, offsetOfMonth)
 
         return self.getOffsetOfMonth(shift_month(other, months, 'start'))