From a803ca4edfc85a5769d44b162a7d2e0f70198afc Mon Sep 17 00:00:00 2001
From: Brock Mendel <jbrockmendel@gmail.com>
Date: Wed, 4 Jul 2018 14:28:22 -0700
Subject: [PATCH 1/4] move ints_to_pytimedelta, normalize_date, fixup imports
 and tests

---
 pandas/_libs/tslib.pyx                       | 53 +-------------------
 pandas/_libs/tslibs/__init__.py              |  8 ++-
 pandas/_libs/tslibs/conversion.pyx           | 29 +++++++++++
 pandas/_libs/tslibs/timedeltas.pyx           | 37 ++++++++++++++
 pandas/_libs/tslibs/timestamps.pyx           |  1 -
 pandas/core/generic.py                       |  2 -
 pandas/tests/tseries/offsets/test_offsets.py |  7 +--
 pandas/tests/tslibs/test_tslib.py            |  5 ++
 8 files changed, 80 insertions(+), 62 deletions(-)

diff --git a/pandas/_libs/tslib.pyx b/pandas/_libs/tslib.pyx
index 61cf582300034..db3a47bc32fda 100644
--- a/pandas/_libs/tslib.pyx
+++ b/pandas/_libs/tslib.pyx
@@ -35,11 +35,10 @@ from cython cimport Py_ssize_t
 
 
 import pytz
-UTC = pytz.utc
 
 
 from tslibs.timedeltas cimport cast_from_unit
-from tslibs.timedeltas import Timedelta
+from tslibs.timedeltas import Timedelta, ints_to_pytimedelta  # noqa:F841
 from tslibs.timezones cimport (is_utc, is_tzlocal, is_fixed_offset,
                                treat_tz_as_pytz, get_dst_info)
 from tslibs.conversion cimport (tz_convert_single, _TSObject,
@@ -185,29 +184,6 @@ def ints_to_pydatetime(ndarray[int64_t] arr, tz=None, freq=None,
     return result
 
 
-def ints_to_pytimedelta(ndarray[int64_t] arr, box=False):
-    # convert an i8 repr to an ndarray of timedelta or Timedelta (if box ==
-    # True)
-
-    cdef:
-        Py_ssize_t i, n = len(arr)
-        int64_t value
-        ndarray[object] result = np.empty(n, dtype=object)
-
-    for i in range(n):
-
-        value = arr[i]
-        if value == NPY_NAT:
-            result[i] = NaT
-        else:
-            if box:
-                result[i] = Timedelta(value)
-            else:
-                result[i] = timedelta(microseconds=int(value) / 1000)
-
-    return result
-
-
 def _test_parse_iso8601(object ts):
     """
     TESTING ONLY: Parse string into Timestamp using iso8601 parser. Used
@@ -740,30 +716,3 @@ cdef inline bint _parse_today_now(str val, int64_t* iresult):
         iresult[0] = Timestamp.today().value
         return True
     return False
-
-# ----------------------------------------------------------------------
-# Some general helper functions
-
-
-cpdef normalize_date(object dt):
-    """
-    Normalize datetime.datetime value to midnight. Returns datetime.date as a
-    datetime.datetime at midnight
-
-    Returns
-    -------
-    normalized : datetime.datetime or Timestamp
-    """
-    if PyDateTime_Check(dt):
-        if not PyDateTime_CheckExact(dt):
-            # i.e. a Timestamp object
-            return dt.replace(hour=0, minute=0, second=0, microsecond=0,
-                              nanosecond=0)
-        else:
-            # regular datetime object
-            return dt.replace(hour=0, minute=0, second=0, microsecond=0)
-            # TODO: Make sure DST crossing is handled correctly here
-    elif PyDate_Check(dt):
-        return datetime(dt.year, dt.month, dt.day)
-    else:
-        raise TypeError('Unrecognized type: %s' % type(dt))
diff --git a/pandas/_libs/tslibs/__init__.py b/pandas/_libs/tslibs/__init__.py
index f3aa0424f0376..64767b2e7a7bc 100644
--- a/pandas/_libs/tslibs/__init__.py
+++ b/pandas/_libs/tslibs/__init__.py
@@ -1,2 +1,8 @@
 # -*- coding: utf-8 -*-
-# cython: profile=False
+# flake8: noqa
+
+from conversion import normalize_date, localize_pydatetime, tz_convert_single
+from nattype import NaT, iNaT
+from np_datetime import OutOfBoundsDatetime
+from timestamps import Timestamp
+from timedeltas import delta_to_nanoseconds, ints_to_pytimedelta, Timedelta
diff --git a/pandas/_libs/tslibs/conversion.pyx b/pandas/_libs/tslibs/conversion.pyx
index f825a4c8ed2c1..fd4b0b11065ed 100644
--- a/pandas/_libs/tslibs/conversion.pyx
+++ b/pandas/_libs/tslibs/conversion.pyx
@@ -1025,6 +1025,35 @@ cdef inline str _render_tstamp(int64_t val):
 # ----------------------------------------------------------------------
 # Normalization
 
+
+def normalize_date(object dt):
+    """
+    Normalize datetime.datetime value to midnight. Returns datetime.date as a
+    datetime.datetime at midnight
+
+    Parameters
+    ----------
+    dt : date, datetime, or Timestamp
+
+    Returns
+    -------
+    normalized : datetime.datetime or Timestamp
+    """
+    if PyDateTime_Check(dt):
+        if not PyDateTime_CheckExact(dt):
+            # i.e. a Timestamp object
+            return dt.replace(hour=0, minute=0, second=0, microsecond=0,
+                              nanosecond=0)
+        else:
+            # regular datetime object
+            return dt.replace(hour=0, minute=0, second=0, microsecond=0)
+            # TODO: Make sure DST crossing is handled correctly here
+    elif PyDate_Check(dt):
+        return datetime(dt.year, dt.month, dt.day)
+    else:
+        raise TypeError('Unrecognized type: %s' % type(dt))
+
+
 @cython.wraparound(False)
 @cython.boundscheck(False)
 def date_normalize(ndarray[int64_t] stamps, tz=None):
diff --git a/pandas/_libs/tslibs/timedeltas.pyx b/pandas/_libs/tslibs/timedeltas.pyx
index 27066af0be3b9..02430e6758dfe 100644
--- a/pandas/_libs/tslibs/timedeltas.pyx
+++ b/pandas/_libs/tslibs/timedeltas.pyx
@@ -79,6 +79,43 @@ cdef dict timedelta_abbrevs = { 'D': 'd',
 
 _no_input = object()
 
+# ----------------------------------------------------------------------
+# API
+
+def ints_to_pytimedelta(ndarray[int64_t] arr, box=False):
+    """
+    convert an i8 repr to an ndarray of timedelta or Timedelta (if box ==
+    True)
+
+    Parameters
+    ----------
+    arr : ndarray[int64_t]
+    box : bool, default False
+
+    Returns
+    -------
+    result : ndarray[object]
+        array of Timedelta or timedeltas objects
+    """
+    cdef:
+        Py_ssize_t i, n = len(arr)
+        int64_t value
+        ndarray[object] result = np.empty(n, dtype=object)
+
+    for i in range(n):
+
+        value = arr[i]
+        if value == NPY_NAT:
+            result[i] = NaT
+        else:
+            if box:
+                result[i] = Timedelta(value)
+            else:
+                result[i] = timedelta(microseconds=int(value) / 1000)
+
+    return result
+
+
 # ----------------------------------------------------------------------
 
 cpdef int64_t delta_to_nanoseconds(delta) except? -1:
diff --git a/pandas/_libs/tslibs/timestamps.pyx b/pandas/_libs/tslibs/timestamps.pyx
index 54d29cea44555..401ba76e341b2 100644
--- a/pandas/_libs/tslibs/timestamps.pyx
+++ b/pandas/_libs/tslibs/timestamps.pyx
@@ -645,7 +645,6 @@ class Timestamp(_Timestamp):
             return NaT
 
         if is_string_object(freq):
-            from pandas.tseries.frequencies import to_offset
             freq = to_offset(freq)
 
         return create_timestamp_from_ts(ts.value, ts.dts, ts.tzinfo, freq)
diff --git a/pandas/core/generic.py b/pandas/core/generic.py
index 26c23b84a9c04..818dd1b408518 100644
--- a/pandas/core/generic.py
+++ b/pandas/core/generic.py
@@ -7156,7 +7156,6 @@ def first(self, offset):
         at_time : Select values at a particular time of the day
         between_time : Select values between particular times of the day
         """
-        from pandas.tseries.frequencies import to_offset
         if not isinstance(self.index, DatetimeIndex):
             raise TypeError("'first' only supports a DatetimeIndex index")
 
@@ -7220,7 +7219,6 @@ def last(self, offset):
         at_time : Select values at a particular time of the day
         between_time : Select values between particular times of the day
         """
-        from pandas.tseries.frequencies import to_offset
         if not isinstance(self.index, DatetimeIndex):
             raise TypeError("'last' only supports a DatetimeIndex index")
 
diff --git a/pandas/tests/tseries/offsets/test_offsets.py b/pandas/tests/tseries/offsets/test_offsets.py
index 0c5470e7bd932..a5cd839c1472f 100644
--- a/pandas/tests/tseries/offsets/test_offsets.py
+++ b/pandas/tests/tseries/offsets/test_offsets.py
@@ -33,7 +33,7 @@
 import pandas.tseries.offsets as offsets
 from pandas.io.pickle import read_pickle
 from pandas._libs.tslibs import timezones
-from pandas._libs.tslib import normalize_date, NaT, Timestamp
+from pandas._libs.tslib import NaT, Timestamp
 import pandas._libs.tslib as tslib
 import pandas.util.testing as tm
 from pandas.tseries.holiday import USFederalHolidayCalendar
@@ -59,11 +59,6 @@ def test_ole2datetime():
         ole2datetime(60)
 
 
-def test_normalize_date():
-    actual = normalize_date(datetime(2007, 10, 1, 1, 12, 5, 10))
-    assert actual == datetime(2007, 10, 1)
-
-
 def test_to_m8():
     valb = datetime(2007, 10, 1)
     valu = _to_m8(valb)
diff --git a/pandas/tests/tslibs/test_tslib.py b/pandas/tests/tslibs/test_tslib.py
index 2641c016e8674..484ec71cdc4c1 100644
--- a/pandas/tests/tslibs/test_tslib.py
+++ b/pandas/tests/tslibs/test_tslib.py
@@ -16,3 +16,8 @@ def test_normalize_date():
 
     result = tslib.normalize_date(value)
     assert (result == datetime(2012, 9, 7))
+
+    value = datetime(2007, 10, 1, 1, 12, 5, 10)
+
+    actual = tslib.normalize_date(value)
+    assert actual == datetime(2007, 10, 1)

From feae5f332035005f7604d83ffcd54baa1e7ed8da Mon Sep 17 00:00:00 2001
From: Brock Mendel <jbrockmendel@gmail.com>
Date: Wed, 4 Jul 2018 16:08:22 -0700
Subject: [PATCH 2/4] extra import

---
 pandas/_libs/tslib.pyx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/_libs/tslib.pyx b/pandas/_libs/tslib.pyx
index db3a47bc32fda..c1a0e58a4fb1a 100644
--- a/pandas/_libs/tslib.pyx
+++ b/pandas/_libs/tslib.pyx
@@ -45,7 +45,7 @@ from tslibs.conversion cimport (tz_convert_single, _TSObject,
                                 convert_datetime_to_tsobject,
                                 get_datetime64_nanos,
                                 tz_convert_utc_to_tzlocal)
-from tslibs.conversion import tz_convert_single
+from tslibs.conversion import tz_convert_single, normalize_date  # noqa:F841
 
 from tslibs.nattype import NaT, nat_strings, iNaT
 from tslibs.nattype cimport checknull_with_nat, NPY_NAT

From 6a9afa4c6bac4047d069169473973267d6ea3829 Mon Sep 17 00:00:00 2001
From: Brock Mendel <jbrockmendel@gmail.com>
Date: Wed, 4 Jul 2018 17:48:14 -0700
Subject: [PATCH 3/4] make imports explicit

---
 pandas/_libs/tslibs/__init__.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/pandas/_libs/tslibs/__init__.py b/pandas/_libs/tslibs/__init__.py
index 64767b2e7a7bc..22307f70ebe52 100644
--- a/pandas/_libs/tslibs/__init__.py
+++ b/pandas/_libs/tslibs/__init__.py
@@ -1,8 +1,8 @@
 # -*- coding: utf-8 -*-
 # flake8: noqa
 
-from conversion import normalize_date, localize_pydatetime, tz_convert_single
-from nattype import NaT, iNaT
-from np_datetime import OutOfBoundsDatetime
-from timestamps import Timestamp
-from timedeltas import delta_to_nanoseconds, ints_to_pytimedelta, Timedelta
+from .conversion import normalize_date, localize_pydatetime, tz_convert_single
+from .nattype import NaT, iNaT
+from .np_datetime import OutOfBoundsDatetime
+from .timestamps import Timestamp
+from .timedeltas import delta_to_nanoseconds, ints_to_pytimedelta, Timedelta

From 94239a00587e4cd73fd022eb46650b71d2771e4a Mon Sep 17 00:00:00 2001
From: Brock Mendel <jbrockmendel@gmail.com>
Date: Wed, 4 Jul 2018 19:12:07 -0700
Subject: [PATCH 4/4] whitespace fixup

---
 pandas/_libs/tslibs/timedeltas.pyx | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pandas/_libs/tslibs/timedeltas.pyx b/pandas/_libs/tslibs/timedeltas.pyx
index 02430e6758dfe..76849f2116123 100644
--- a/pandas/_libs/tslibs/timedeltas.pyx
+++ b/pandas/_libs/tslibs/timedeltas.pyx
@@ -79,6 +79,7 @@ cdef dict timedelta_abbrevs = { 'D': 'd',
 
 _no_input = object()
 
+
 # ----------------------------------------------------------------------
 # API