From e9b40190a29aa7ba5b9b739fe04f75c6bbc340e0 Mon Sep 17 00:00:00 2001
From: Andrew Wieteska <andrew.r.wieteska@gmail.com>
Date: Sun, 24 Jan 2021 23:28:25 -0500
Subject: [PATCH 1/3] add DateOffset

---
 pandas/_typing.py    |  2 ++
 pandas/core/frame.py | 19 +++++++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/pandas/_typing.py b/pandas/_typing.py
index 0b50dd69f7abb..0435b20447e7c 100644
--- a/pandas/_typing.py
+++ b/pandas/_typing.py
@@ -30,6 +30,7 @@
     from typing import final
 
     from pandas._libs import Period, Timedelta, Timestamp
+    from pandas._libs.tslibs.offsets import DateOffset
 
     from pandas.core.dtypes.dtypes import ExtensionDtype
 
@@ -92,6 +93,7 @@
 Ordered = Optional[bool]
 JSONSerializable = Optional[Union[PythonScalar, List, Dict]]
 Axes = Collection
+Frequency = Union[str, DateOffset]
 
 # dtypes
 NpDtype = Union[str, np.dtype]
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index 1d8280ae3b2f1..78f7ec47e99cf 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -59,6 +59,7 @@
     FloatFormatType,
     FormattersType,
     FrameOrSeriesUnion,
+    Frequency,
     IndexKeyFunc,
     IndexLabel,
     Label,
@@ -4582,7 +4583,11 @@ def _replace_columnwise(
 
     @doc(NDFrame.shift, klass=_shared_doc_kwargs["klass"])
     def shift(
-        self, periods=1, freq=None, axis: Axis = 0, fill_value=lib.no_default
+        self,
+        periods=1,
+        freq: Optional[Frequency] = None,
+        axis: Axis = 0,
+        fill_value=lib.no_default,
     ) -> DataFrame:
         axis = self._get_axis_number(axis)
 
@@ -9371,7 +9376,7 @@ def quantile(
     @doc(NDFrame.asfreq, **_shared_doc_kwargs)
     def asfreq(
         self,
-        freq,
+        freq: Frequency,
         method=None,
         how: Optional[str] = None,
         normalize: bool = False,
@@ -9417,7 +9422,11 @@ def resample(
         )
 
     def to_timestamp(
-        self, freq=None, how: str = "start", axis: Axis = 0, copy: bool = True
+        self,
+        freq: Optional[Frequency] = None,
+        how: str = "start",
+        axis: Axis = 0,
+        copy: bool = True,
     ) -> DataFrame:
         """
         Cast to DatetimeIndex of timestamps, at *beginning* of period.
@@ -9450,7 +9459,9 @@ def to_timestamp(
         setattr(new_obj, axis_name, new_ax)
         return new_obj
 
-    def to_period(self, freq=None, axis: Axis = 0, copy: bool = True) -> DataFrame:
+    def to_period(
+        self, freq: Optional[Frequency] = None, axis: Axis = 0, copy: bool = True
+    ) -> DataFrame:
         """
         Convert DataFrame from DatetimeIndex to PeriodIndex.
 

From 7b24af7472d87c29d49811548b331963d0c93022 Mon Sep 17 00:00:00 2001
From: Andrew Wieteska <andrew.r.wieteska@gmail.com>
Date: Fri, 19 Feb 2021 17:05:34 -0500
Subject: [PATCH 2/3] fix import

---
 pandas/_typing.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/_typing.py b/pandas/_typing.py
index 951883d6e56b1..2c74498fb35a9 100644
--- a/pandas/_typing.py
+++ b/pandas/_typing.py
@@ -43,7 +43,6 @@
         Timedelta,
         Timestamp,
     )
-    from pandas._libs.tslibs.offsets import DateOffset
 
     from pandas.core.dtypes.dtypes import ExtensionDtype
 
@@ -65,6 +64,7 @@
     from pandas.core.window.rolling import BaseWindow
 
     from pandas.io.formats.format import EngFormatter
+    from pandas.tseries.offsets import DateOffset
 else:
     # typing.final does not exist until py38
     final = lambda x: x

From 0fbc8995b9dfd0c659e855c40c7dbfdbbf4d1503 Mon Sep 17 00:00:00 2001
From: Andrew Wieteska <andrew.r.wieteska@gmail.com>
Date: Fri, 19 Feb 2021 17:22:16 -0500
Subject: [PATCH 3/3] use string quotes

---
 pandas/_typing.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/_typing.py b/pandas/_typing.py
index 2c74498fb35a9..c50d532f40dd7 100644
--- a/pandas/_typing.py
+++ b/pandas/_typing.py
@@ -111,7 +111,7 @@
 Suffixes = Tuple[str, str]
 Ordered = Optional[bool]
 JSONSerializable = Optional[Union[PythonScalar, List, Dict]]
-Frequency = Union[str, DateOffset]
+Frequency = Union[str, "DateOffset"]
 Axes = Collection[Any]
 
 # dtypes