Fix some imports and move whatsnew

Author: reidy-p

doc/source/whatsnew/v0.24.0.txt

@@ -159,6 +159,39 @@ For situations where you need an ``ndarray`` of ``Interval`` objects, use
    np.asarray(idx)
    idx.values.astype(object)
 
+.. _whatsnew_0240.api_breaking.period_end_time:
+
+Time values in ``dt.end_time`` and ``to_timestamp(how='end')``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The time values in :class:`Period` and :class:`PeriodIndex` objects are now set
+to '23:59:59.999999999' when calling :attr:`Series.dt.end_time`, :attr:`Period.end_time`,
+:attr:`PeriodIndex.end_time`, :func:`Period.to_timestamp()` with ``how='end'``,
+or :func:`PeriodIndex.to_timestamp()` with ``how='end'`` (:issue:`17157`)
+
+Previous Behavior:
+
+.. code-block:: ipython
+
+   In [2]: p = pd.Period('2017-01-01', 'D')
+   In [3]: pi = pd.PeriodIndex([p])
+
+   In [4]: pd.Series(pi).dt.end_time[0]
+   Out[4]: Timestamp(2017-01-01 00:00:00)
+
+   In [5]: p.end_time
+   Out[5]: Timestamp(2017-01-01 23:59:59.999999999)
+
+Current Behavior:
+
+.. ipython:: python
+
+   p = pd.Period('2017-01-01', 'D')
+   pi = pd.PeriodIndex([p])
+
+   pd.Series(pi).dt.end_time[0]
+
+   p.end_time
 
 .. _whatsnew_0240.api.datetimelike.normalize:
 

pandas/_libs/tslibs/period.pyx

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # cython: profile=False
-from datetime import datetime, date, timedelta
+from datetime import datetime, date
 
 from cpython cimport (
     PyUnicode_Check,
@@ -35,7 +35,7 @@ cdef extern from "../src/datetime/np_datetime.h":
 cimport util
 from util cimport is_period_object, is_string_object, INT32_MIN
 
-from pandas._libs.tslib import Timedelta
+from pandas._libs.tslibs.timedeltas import Timedelta
 from timestamps import Timestamp
 from timezones cimport is_utc, is_tzlocal, get_dst_info
 from timedeltas cimport delta_to_nanoseconds

pandas/core/indexes/datetimes.py

@@ -1792,7 +1792,7 @@ def _generate_regular_range(start, end, periods, freq):
     else:
 
         xdr = generate_range(start=start, end=end,
-                             periods=periods, offset=offset)
+                             periods=periods, offset=freq)
 
         dates = list(xdr)
         # utc = len(dates) > 0 and dates[0].tzinfo is not None

pandas/core/indexes/period.py

@@ -25,7 +25,7 @@
 from pandas.core.tools.datetimes import parse_time_string
 
 from pandas._libs.lib import infer_dtype
-from pandas._libs import tslib, index as libindex
+from pandas._libs import tslib, index as libindex, Timedelta
 from pandas._libs.tslibs.period import (Period, IncompatibleFrequency,
                                         DIFFERENT_FREQ_INDEX,
                                         _validate_end_alias)
@@ -507,6 +507,7 @@ def to_timestamp(self, freq=None, how='start'):
         end = how == 'E'
         if end:
             if freq == 'B':
+                # roll forward to ensure we land on B date
                 adjust = Timedelta(1, 'D') - Timedelta(1, 'ns')
                 return self.to_timestamp(how='start') + adjust
             else: