From f6207639ac319374075bd24c902c88e744cda354 Mon Sep 17 00:00:00 2001
From: MarcoGorelli <33491632+MarcoGorelli@users.noreply.github.com>
Date: Wed, 8 Nov 2023 20:51:04 +0000
Subject: [PATCH 1/3] add column.shift

---
 .../dataframe_api/column_object.py                  | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/spec/API_specification/dataframe_api/column_object.py b/spec/API_specification/dataframe_api/column_object.py
index 6a83bbce..fed6da50 100644
--- a/spec/API_specification/dataframe_api/column_object.py
+++ b/spec/API_specification/dataframe_api/column_object.py
@@ -811,6 +811,19 @@ def rename(self, name: str) -> Self:
         """
         ...
 
+    def shift(self, offset: int, *, fill_value: Scalar | NullType) -> Self:
+        """Shift values by `offset` positions, filling missing values with `fill_value`.
+
+        For example, if the original column contains values `[1, 4, 2]`, then:
+
+        - `.shift(1)` will return `[null, 1, 4]`,
+        - `.shift(-1)` will return `[4, 2, null]`,
+        - `.shift(1, fill_value=999)` will return `[999, 1, 4]`,
+        """
+        ...
+
+    # --- temporal methods ---
+
     def year(self) -> Self:
         """Return 'year' component of each element of `Date` and `Datetime` columns.
 

From 7e42254a309f15dacf8253fbfdd7cdb19c1cc423 Mon Sep 17 00:00:00 2001
From: MarcoGorelli <33491632+MarcoGorelli@users.noreply.github.com>
Date: Wed, 8 Nov 2023 20:57:10 +0000
Subject: [PATCH 2/3] extra docs

---
 spec/API_specification/dataframe_api/column_object.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/spec/API_specification/dataframe_api/column_object.py b/spec/API_specification/dataframe_api/column_object.py
index fed6da50..497b52c8 100644
--- a/spec/API_specification/dataframe_api/column_object.py
+++ b/spec/API_specification/dataframe_api/column_object.py
@@ -819,6 +819,14 @@ def shift(self, offset: int, *, fill_value: Scalar | NullType) -> Self:
         - `.shift(1)` will return `[null, 1, 4]`,
         - `.shift(-1)` will return `[4, 2, null]`,
         - `.shift(1, fill_value=999)` will return `[999, 1, 4]`,
+    
+        Parameters
+        ----------
+            offset
+                How many positions to shift by.
+            fill_value 
+                Value to use for filling missing values. Must be of the Python
+                scalar type matching the dtype of the column.
         """
         ...
 

From 475ac45c27b14b96ac1f29bddd208735bce5c2f4 Mon Sep 17 00:00:00 2001
From: MarcoGorelli <33491632+MarcoGorelli@users.noreply.github.com>
Date: Tue, 14 Nov 2023 08:09:27 +0000
Subject: [PATCH 3/3] formatting, remove fill_value

---
 .../API_specification/dataframe_api/column_object.py | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/spec/API_specification/dataframe_api/column_object.py b/spec/API_specification/dataframe_api/column_object.py
index 497b52c8..79db7699 100644
--- a/spec/API_specification/dataframe_api/column_object.py
+++ b/spec/API_specification/dataframe_api/column_object.py
@@ -811,22 +811,18 @@ def rename(self, name: str) -> Self:
         """
         ...
 
-    def shift(self, offset: int, *, fill_value: Scalar | NullType) -> Self:
-        """Shift values by `offset` positions, filling missing values with `fill_value`.
+    def shift(self, offset: int) -> Self:
+        """Shift values by `offset` positions, filling missing values with `null`.
 
         For example, if the original column contains values `[1, 4, 2]`, then:
 
         - `.shift(1)` will return `[null, 1, 4]`,
         - `.shift(-1)` will return `[4, 2, null]`,
-        - `.shift(1, fill_value=999)` will return `[999, 1, 4]`,
     
         Parameters
         ----------
-            offset
-                How many positions to shift by.
-            fill_value 
-                Value to use for filling missing values. Must be of the Python
-                scalar type matching the dtype of the column.
+        offset
+            How many positions to shift by.
         """
         ...