GH26013 Fix type annotations in pandas/tseries/* (#26014)

Author: gwrome

mypy.ini

@@ -170,15 +170,6 @@ ignore_errors=True
 [mypy-pandas.plotting._core]
 ignore_errors=True
 
-[mypy-pandas.tseries.frequencies]
-ignore_errors=True
-
-[mypy-pandas.tseries.holiday]
-ignore_errors=True
-
-[mypy-pandas.tseries.offsets]
-ignore_errors=True
-
 [mypy-pandas.util._doctools]
 ignore_errors=True
 

pandas/tseries/frequencies.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 from datetime import timedelta
 import re
+from typing import Dict
 
 import numpy as np
 from pytz import AmbiguousTimeError
@@ -37,7 +38,7 @@
 # Offset names ("time rules") and related functions
 
 #: cache of previously seen offsets
-_offset_map = {}
+_offset_map = {}  # type: Dict[str, DateOffset]
 
 
 def get_period_alias(offset_str):

pandas/tseries/holiday.py

@@ -1,4 +1,5 @@
 from datetime import datetime, timedelta
+from typing import List
 import warnings
 
 from dateutil.relativedelta import FR, MO, SA, SU, TH, TU, WE  # noqa
@@ -329,7 +330,7 @@ class AbstractHolidayCalendar(object):
     Abstract interface to create holidays following certain rules.
     """
     __metaclass__ = HolidayCalendarMetaClass
-    rules = []
+    rules = []  # type: List[Holiday]
     start_date = Timestamp(datetime(1970, 1, 1))
     end_date = Timestamp(datetime(2030, 12, 31))
     _cache = None

pandas/tseries/offsets.py

@@ -2,6 +2,7 @@
 from datetime import date, datetime, timedelta
 import functools
 import operator
+from typing import Optional
 
 from dateutil.easter import easter
 import numpy as np
@@ -1582,8 +1583,8 @@ class QuarterOffset(DateOffset):
     """
     Quarter representation - doesn't call super.
     """
-    _default_startingMonth = None
-    _from_name_startingMonth = None
+    _default_startingMonth = None  # type: Optional[int]
+    _from_name_startingMonth = None   # type: Optional[int]
     _adjust_dst = True
     _attributes = frozenset(['n', 'normalize', 'startingMonth'])
     # TODO: Consider combining QuarterOffset and YearOffset __init__ at some