From f18e96bda6171e451a2d3565d18930586bb3b644 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Sun, 9 Apr 2023 20:25:50 +0000
Subject: [PATCH 01/35] Add diff() and round() methods for Index and a test for
 each

---
 pandas/core/indexes/base.py       | 35 +++++++++++++++++++++++++++++++
 pandas/tests/indexes/test_base.py | 18 ++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 8b191897e9409..2014c784861f1 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6756,6 +6756,41 @@ def infer_objects(self, copy: bool = True) -> Index:
             result._references.add_index_reference(result)
         return result
 
+    def diff(self, periods=1):
+        """
+        Computes the difference between consecutive values in the Index object.
+        If periods is greater than 1, computes the difference between values that
+        are `periods` number of positions apart.
+
+        Parameters:
+            periods (int): The number of positions between the current and previous
+            value to compute the difference with. Default is 1.
+
+        Returns:
+        Index
+            A new Index object with the computed differences.
+
+        """
+        return Index(self.to_series().diff(periods))
+
+    def round(self, decimals=0):
+        """
+        Round each value in the Index to the given number of decimals.
+
+        Parameters
+        ----------
+        decimals : int, optional
+            Number of decimal places to round to. If decimals is negative,
+            it specifies the number of positions to the left of the decimal point.
+
+        Returns
+        -------
+        Index
+            A new Index with the rounded values.
+
+        """
+        return Index(self.to_series().round(decimals))
+
     # --------------------------------------------------------------------
     # Generated Arithmetic, Comparison, and Unary Methods
 
diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index e681223933abb..a69a50fc82bc6 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -1270,6 +1270,24 @@ def test_sortlevel_na_position(self):
         expected = Index([np.nan, 1])
         tm.assert_index_equal(result, expected)
 
+    def test_index_diff(self):
+        # GH#19708
+        idx = Index([10, 20, 30, 40, 50])
+        diffs = idx.diff()
+        diffs_period2 = idx.diff(periods=2)
+
+        assert diffs.equals(Index([np.nan, 10, 10, 10, 10]))
+        assert diffs_period2.equals(Index([np.nan, np.nan, 20, 20, 20]))
+
+    def test_index_round(self):
+        # GH#19708
+        idx = Index([1.234, 2.345, 3.456])
+        rounded = idx.round()
+        rounded_2decimals = idx.round(2)
+
+        assert rounded.equals(Index([1, 2, 3]))
+        assert rounded_2decimals.equals(Index([1.23, 2.35, 3.46]))
+
 
 class TestMixedIntIndex(Base):
     # Mostly the tests from common.py for which the results differ

From c6b63d2071ba211602f8db4b213ce79da6559ae0 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Sun, 9 Apr 2023 21:07:13 +0000
Subject: [PATCH 02/35] Fix code style

---
 pandas/core/indexes/base.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 2014c784861f1..f8cdd9d01ab0f 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6756,7 +6756,7 @@ def infer_objects(self, copy: bool = True) -> Index:
             result._references.add_index_reference(result)
         return result
 
-    def diff(self, periods=1):
+    def diff(self, periods: int=1):
         """
         Computes the difference between consecutive values in the Index object.
         If periods is greater than 1, computes the difference between values that
@@ -6773,7 +6773,7 @@ def diff(self, periods=1):
         """
         return Index(self.to_series().diff(periods))
 
-    def round(self, decimals=0):
+    def round(self, decimals: int=0):
         """
         Round each value in the Index to the given number of decimals.
 

From 6329f8c47de3614e51f429e8097b089c12c7b613 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Sun, 9 Apr 2023 21:15:17 +0000
Subject: [PATCH 03/35] Fix code style

---
 pandas/core/indexes/base.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index f8cdd9d01ab0f..bebef4528548f 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6756,7 +6756,7 @@ def infer_objects(self, copy: bool = True) -> Index:
             result._references.add_index_reference(result)
         return result
 
-    def diff(self, periods: int=1):
+    def diff(self, periods: int = 1):
         """
         Computes the difference between consecutive values in the Index object.
         If periods is greater than 1, computes the difference between values that
@@ -6773,7 +6773,7 @@ def diff(self, periods: int=1):
         """
         return Index(self.to_series().diff(periods))
 
-    def round(self, decimals: int=0):
+    def round(self, decimals: int = 0):
         """
         Round each value in the Index to the given number of decimals.
 

From 3ce1f726015d8d93d2063a0b38fb09ae1ddb3ecf Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Mon, 10 Apr 2023 23:34:29 +0000
Subject: [PATCH 04/35] Add pytest.mark.parametrize and fix docstring style

---
 pandas/core/indexes/base.py       |  1 +
 pandas/tests/indexes/test_base.py | 32 +++++++++++++++++++++----------
 2 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index bebef4528548f..b54af796ba0f8 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6759,6 +6759,7 @@ def infer_objects(self, copy: bool = True) -> Index:
     def diff(self, periods: int = 1):
         """
         Computes the difference between consecutive values in the Index object.
+
         If periods is greater than 1, computes the difference between values that
         are `periods` number of positions apart.
 
diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index a69a50fc82bc6..ffa0928c802bf 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -1270,23 +1270,35 @@ def test_sortlevel_na_position(self):
         expected = Index([np.nan, 1])
         tm.assert_index_equal(result, expected)
 
-    def test_index_diff(self):
+    @pytest.mark.parametrize(
+        "periods, expected",
+        [
+            (1, Index([np.nan, 10, 10, 10, 10])),
+            (2, Index([np.nan, np.nan, 20, 20, 20])),
+            (3, Index([np.nan, np.nan, np.nan, 30, 30])),
+        ],
+    )
+    def test_index_diff(self, periods, expected):
         # GH#19708
         idx = Index([10, 20, 30, 40, 50])
-        diffs = idx.diff()
-        diffs_period2 = idx.diff(periods=2)
+        result = idx.diff()
 
-        assert diffs.equals(Index([np.nan, 10, 10, 10, 10]))
-        assert diffs_period2.equals(Index([np.nan, np.nan, 20, 20, 20]))
+        tm.assert_index_equal(result, expected)
 
-    def test_index_round(self):
+    @pytest.mark.parametrize(
+        "decimals, expected",
+        [
+            (0, Index([1, 2, 3])),
+            (1, Index([1.2, 2.3, 3.5])),
+            (2, Index([1.23, 2.35, 3.46])),
+        ],
+    )
+    def test_index_round(self, decimals, expected):
         # GH#19708
         idx = Index([1.234, 2.345, 3.456])
-        rounded = idx.round()
-        rounded_2decimals = idx.round(2)
+        result = idx.round()
 
-        assert rounded.equals(Index([1, 2, 3]))
-        assert rounded_2decimals.equals(Index([1.23, 2.35, 3.46]))
+        tm.assert_index_equal(result, expected)
 
 
 class TestMixedIntIndex(Base):

From 57032c9d944f7fc50e6923e13fc67a6f959f2452 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Mon, 10 Apr 2023 23:51:30 +0000
Subject: [PATCH 05/35] Move Index call

---
 pandas/tests/indexes/test_base.py | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index ffa0928c802bf..fb60a1be176ed 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -1271,32 +1271,34 @@ def test_sortlevel_na_position(self):
         tm.assert_index_equal(result, expected)
 
     @pytest.mark.parametrize(
-        "periods, expected",
+        "periods, expected_results",
         [
-            (1, Index([np.nan, 10, 10, 10, 10])),
-            (2, Index([np.nan, np.nan, 20, 20, 20])),
-            (3, Index([np.nan, np.nan, np.nan, 30, 30])),
+            (1, [np.nan, 10, 10, 10, 10]),
+            (2, [np.nan, np.nan, 20, 20, 20]),
+            (3, [np.nan, np.nan, np.nan, 30, 30]),
         ],
     )
-    def test_index_diff(self, periods, expected):
+    def test_index_diff(self, periods, expected_results):
         # GH#19708
         idx = Index([10, 20, 30, 40, 50])
         result = idx.diff()
+        expected = Index(expected_results)
 
         tm.assert_index_equal(result, expected)
 
     @pytest.mark.parametrize(
-        "decimals, expected",
+        "decimals, expected_results",
         [
-            (0, Index([1, 2, 3])),
-            (1, Index([1.2, 2.3, 3.5])),
-            (2, Index([1.23, 2.35, 3.46])),
+            (0, [1, 2, 3]),
+            (1, [1.2, 2.3, 3.5]),
+            (2, [1.23, 2.35, 3.46]),
         ],
     )
-    def test_index_round(self, decimals, expected):
+    def test_index_round(self, decimals, expected_results):
         # GH#19708
         idx = Index([1.234, 2.345, 3.456])
         result = idx.round()
+        expected = Index(expected_results)
 
         tm.assert_index_equal(result, expected)
 

From 9f4680570d0cb8c9c2c321d95a7cb5a398cbc64d Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 12:04:41 +0000
Subject: [PATCH 06/35] Fix diff() and round() call

---
 pandas/tests/indexes/test_base.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index fb60a1be176ed..790534f35abd5 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -1281,7 +1281,7 @@ def test_sortlevel_na_position(self):
     def test_index_diff(self, periods, expected_results):
         # GH#19708
         idx = Index([10, 20, 30, 40, 50])
-        result = idx.diff()
+        result = idx.diff(periods)
         expected = Index(expected_results)
 
         tm.assert_index_equal(result, expected)
@@ -1297,7 +1297,7 @@ def test_index_diff(self, periods, expected_results):
     def test_index_round(self, decimals, expected_results):
         # GH#19708
         idx = Index([1.234, 2.345, 3.456])
-        result = idx.round()
+        result = idx.round(decimals)
         expected = Index(expected_results)
 
         tm.assert_index_equal(result, expected)

From 76742e42bc8f192495bb5210808a42345eea38a5 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 12:38:28 +0000
Subject: [PATCH 07/35] Change Index to float

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

diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index 790534f35abd5..db317a819c520 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -1289,7 +1289,7 @@ def test_index_diff(self, periods, expected_results):
     @pytest.mark.parametrize(
         "decimals, expected_results",
         [
-            (0, [1, 2, 3]),
+            (0, [1.0, 2.0, 3.0]),
             (1, [1.2, 2.3, 3.5]),
             (2, [1.23, 2.35, 3.46]),
         ],

From 1eeab2a72ddd8087ec497d203a1573e59c36aa82 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 14:13:33 +0000
Subject: [PATCH 08/35] Fix docstring style

---
 pandas/core/indexes/base.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index b54af796ba0f8..e0ccae1a63820 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6768,6 +6768,7 @@ def diff(self, periods: int = 1):
             value to compute the difference with. Default is 1.
 
         Returns:
+        -------
         Index
             A new Index object with the computed differences.
 

From fe713fd5abccad5700e8dbe8fd0a7299ae3c1bf7 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 15:46:08 +0000
Subject: [PATCH 09/35] Fix docstring style

---
 pandas/core/indexes/base.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index e0ccae1a63820..a74c7faea0e12 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6763,11 +6763,13 @@ def diff(self, periods: int = 1):
         If periods is greater than 1, computes the difference between values that
         are `periods` number of positions apart.
 
-        Parameters:
-            periods (int): The number of positions between the current and previous
+        Parameters
+        ----------
+        periods : int, optional 
+            The number of positions between the current and previous
             value to compute the difference with. Default is 1.
 
-        Returns:
+        Returns
         -------
         Index
             A new Index object with the computed differences.

From 837ab45515e9e35e7c16b2d8f38888443dbaa924 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 15:56:34 +0000
Subject: [PATCH 10/35] Fix pre-commit errors

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

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index a74c7faea0e12..022a3b1cfb6e2 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6765,7 +6765,7 @@ def diff(self, periods: int = 1):
 
         Parameters
         ----------
-        periods : int, optional 
+        periods : int, optional
             The number of positions between the current and previous
             value to compute the difference with. Default is 1.
 

From 8925abaaecbd4d66d94decd6b48755ed76fd0892 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 20:49:07 +0000
Subject: [PATCH 11/35] Add example section in docstring and change return
 statement

---
 pandas/core/indexes/base.py | 39 +++++++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 022a3b1cfb6e2..821f825c6aeca 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6774,8 +6774,27 @@ def diff(self, periods: int = 1):
         Index
             A new Index object with the computed differences.
 
+        Example
+        -------
+        >>> import pandas as pd
+        >>> idx = pd.Index([10, 20, 30, 40, 50])
+        >>> diff_idx = idx.diff()
+        >>> print(diff_idx)
+        Float64Index([nan, 10.0, 10.0, 10.0, 10.0], dtype='float64')
+
+        This example creates a new `Index` object `idx` with values
+        `[10, 20, 30, 40, 50]`.
+
+        The `diff` method is then used to compute the difference between
+        consecutive values in the `Index` object.
+
+        The resulting `diff_idx` object has the values `[nan, 10.0, 10.0, 10.0, 10.0]`.
+
+        Note that the first value is `nan` since there is no previous value to compute
+        the difference with.
+
         """
-        return Index(self.to_series().diff(periods))
+        return self._constructor(self.to_series().diff(periods))
 
     def round(self, decimals: int = 0):
         """
@@ -6792,8 +6811,24 @@ def round(self, decimals: int = 0):
         Index
             A new Index with the rounded values.
 
+        Example
+        -------
+        >>> import pandas as pd
+        >>> idx = pd.Index([10.1234, 20.5678, 30.9123, 40.4567, 50.7890])
+        >>> rounded_idx = idx.round(decimals=2)
+        >>> print(rounded_idx)
+        Float64Index([10.12, 20.57, 30.91, 40.46, 50.79], dtype='float64')
+
+        This example creates a new `Index` object `idx` with values
+        `[10.1234, 20.5678, 30.9123, 40.4567, 50.7890]`.
+
+        The `round` method is then used to round each value to two decimal places.
+
+        The resulting `rounded_idx` object has the values
+        `[10.12, 20.57, 30.91, 40.46, 50.79]`.
+
         """
-        return Index(self.to_series().round(decimals))
+        return self._constructor(self.to_series().round(decimals))
 
     # --------------------------------------------------------------------
     # Generated Arithmetic, Comparison, and Unary Methods

From 73902304b730206eaeebb16b1587cee27186be34 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 21:30:51 +0000
Subject: [PATCH 12/35] Fix docstring example section

---
 pandas/core/indexes/base.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 821f825c6aeca..12bd44816a8fb 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6780,7 +6780,7 @@ def diff(self, periods: int = 1):
         >>> idx = pd.Index([10, 20, 30, 40, 50])
         >>> diff_idx = idx.diff()
         >>> print(diff_idx)
-        Float64Index([nan, 10.0, 10.0, 10.0, 10.0], dtype='float64')
+        Index([nan, 10.0, 10.0, 10.0, 10.0], dtype='float64')
 
         This example creates a new `Index` object `idx` with values
         `[10, 20, 30, 40, 50]`.
@@ -6817,7 +6817,7 @@ def round(self, decimals: int = 0):
         >>> idx = pd.Index([10.1234, 20.5678, 30.9123, 40.4567, 50.7890])
         >>> rounded_idx = idx.round(decimals=2)
         >>> print(rounded_idx)
-        Float64Index([10.12, 20.57, 30.91, 40.46, 50.79], dtype='float64')
+        Index([10.12, 20.57, 30.91, 40.46, 50.79], dtype='float64')
 
         This example creates a new `Index` object `idx` with values
         `[10.1234, 20.5678, 30.9123, 40.4567, 50.7890]`.

From 8cce64207ecd03dcea7e63d6df54d64f7a5c2ac4 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 23:57:12 +0000
Subject: [PATCH 13/35] Fix docstring

---
 pandas/core/indexes/base.py | 33 ++++++---------------------------
 1 file changed, 6 insertions(+), 27 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 12bd44816a8fb..785c57a8a6cbf 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6774,25 +6774,13 @@ def diff(self, periods: int = 1):
         Index
             A new Index object with the computed differences.
 
-        Example
-        -------
+        Examples
+        --------
         >>> import pandas as pd
         >>> idx = pd.Index([10, 20, 30, 40, 50])
-        >>> diff_idx = idx.diff()
-        >>> print(diff_idx)
+        >>> idx.diff()
         Index([nan, 10.0, 10.0, 10.0, 10.0], dtype='float64')
 
-        This example creates a new `Index` object `idx` with values
-        `[10, 20, 30, 40, 50]`.
-
-        The `diff` method is then used to compute the difference between
-        consecutive values in the `Index` object.
-
-        The resulting `diff_idx` object has the values `[nan, 10.0, 10.0, 10.0, 10.0]`.
-
-        Note that the first value is `nan` since there is no previous value to compute
-        the difference with.
-
         """
         return self._constructor(self.to_series().diff(periods))
 
@@ -6811,22 +6799,13 @@ def round(self, decimals: int = 0):
         Index
             A new Index with the rounded values.
 
-        Example
-        -------
+        Examples
+        --------
         >>> import pandas as pd
         >>> idx = pd.Index([10.1234, 20.5678, 30.9123, 40.4567, 50.7890])
-        >>> rounded_idx = idx.round(decimals=2)
-        >>> print(rounded_idx)
+        >>> idx.round(decimals=2)
         Index([10.12, 20.57, 30.91, 40.46, 50.79], dtype='float64')
 
-        This example creates a new `Index` object `idx` with values
-        `[10.1234, 20.5678, 30.9123, 40.4567, 50.7890]`.
-
-        The `round` method is then used to round each value to two decimal places.
-
-        The resulting `rounded_idx` object has the values
-        `[10.12, 20.57, 30.91, 40.46, 50.79]`.
-
         """
         return self._constructor(self.to_series().round(decimals))
 

From 4a9cca3cfe70c08901a86f2e13618fdede96449f Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Thu, 13 Apr 2023 03:39:50 +0300
Subject: [PATCH 14/35] Add whatsnew in v2.1.0.rst

---
 doc/source/whatsnew/v2.1.0.rst | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/doc/source/whatsnew/v2.1.0.rst b/doc/source/whatsnew/v2.1.0.rst
index 9f5d6011a7780..0b3a2a005ed95 100644
--- a/doc/source/whatsnew/v2.1.0.rst
+++ b/doc/source/whatsnew/v2.1.0.rst
@@ -67,6 +67,40 @@ Also, note that :meth:`Categorical.map` implicitly has had its ``na_action`` set
 This has been deprecated and will :meth:`Categorical.map` in the future change the default
 to ``na_action=None``, like for all the other array types.
 
+.. _whatsnew_210.enhancements.enhancement3:
+
+Index now has diff() and round() methods
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The :class:`Index` object in Pandas version 2.1.0 has two new methods: :meth:`diff()` and :meth:`round()`. 
+These methods are useful for performing computations on the values in an :class:`Index` object (:issue:`19708`).
+
+The :meth:`diff()` method computes the difference between consecutive values in the index. 
+If the periods parameter is greater than 1, it computes the difference between values 
+that are periods number of positions apart.
+
+For example:
+
+.. code-block:: python
+  
+    import pandas as pd
+
+    idx = pd.Index([10, 20, 30, 40, 50])
+    print(idx.diff())  # Output: [nan, 10.0, 10.0, 10.0, 10.0]
+
+The :meth:`round()` method rounds each value in the index to the given number of decimals.
+
+For example:
+
+.. code-block:: python
+
+    import pandas as pd
+
+    idx = pd.Index([10.1234, 20.5678, 30.9123, 40.4567, 50.7890])
+    print(idx.round(decimals=2))  # Output: [10.12, 20.57, 30.91, 40.46, 50.79]
+    
+We hope these new methods enhance your experience with Pandas!
+
 .. _whatsnew_210.enhancements.other:
 
 Other enhancements

From d7eaf04eba7d5c42cf6401140c5590b0fe94c003 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Thu, 13 Apr 2023 04:08:31 +0300
Subject: [PATCH 15/35] Fix whatsnew entry

---
 doc/source/whatsnew/v2.1.0.rst | 36 +---------------------------------
 1 file changed, 1 insertion(+), 35 deletions(-)

diff --git a/doc/source/whatsnew/v2.1.0.rst b/doc/source/whatsnew/v2.1.0.rst
index 0b3a2a005ed95..dc219c51044a8 100644
--- a/doc/source/whatsnew/v2.1.0.rst
+++ b/doc/source/whatsnew/v2.1.0.rst
@@ -67,40 +67,6 @@ Also, note that :meth:`Categorical.map` implicitly has had its ``na_action`` set
 This has been deprecated and will :meth:`Categorical.map` in the future change the default
 to ``na_action=None``, like for all the other array types.
 
-.. _whatsnew_210.enhancements.enhancement3:
-
-Index now has diff() and round() methods
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-The :class:`Index` object in Pandas version 2.1.0 has two new methods: :meth:`diff()` and :meth:`round()`. 
-These methods are useful for performing computations on the values in an :class:`Index` object (:issue:`19708`).
-
-The :meth:`diff()` method computes the difference between consecutive values in the index. 
-If the periods parameter is greater than 1, it computes the difference between values 
-that are periods number of positions apart.
-
-For example:
-
-.. code-block:: python
-  
-    import pandas as pd
-
-    idx = pd.Index([10, 20, 30, 40, 50])
-    print(idx.diff())  # Output: [nan, 10.0, 10.0, 10.0, 10.0]
-
-The :meth:`round()` method rounds each value in the index to the given number of decimals.
-
-For example:
-
-.. code-block:: python
-
-    import pandas as pd
-
-    idx = pd.Index([10.1234, 20.5678, 30.9123, 40.4567, 50.7890])
-    print(idx.round(decimals=2))  # Output: [10.12, 20.57, 30.91, 40.46, 50.79]
-    
-We hope these new methods enhance your experience with Pandas!
-
 .. _whatsnew_210.enhancements.other:
 
 Other enhancements
@@ -121,8 +87,8 @@ Other enhancements
 - :meth:`DataFrame.applymap` now uses the :meth:`~api.extensions.ExtensionArray.map` method of underlying :class:`api.extensions.ExtensionArray` instances (:issue:`52219`)
 - :meth:`arrays.SparseArray.map` now supports ``na_action`` (:issue:`52096`).
 - Add dtype of categories to ``repr`` information of :class:`CategoricalDtype` (:issue:`52179`)
+- Add :meth:`diff()` and :meth:`round()` for :class:`Index` (:issue:`19708`)
 -
-
 .. ---------------------------------------------------------------------------
 .. _whatsnew_210.notable_bug_fixes:
 

From 22b3e59d507c62979c1c0e6dc7816a7957b9c380 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Thu, 13 Apr 2023 04:16:37 +0300
Subject: [PATCH 16/35] Resolve conflict

---
 doc/source/whatsnew/v2.1.0.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/source/whatsnew/v2.1.0.rst b/doc/source/whatsnew/v2.1.0.rst
index dc219c51044a8..ac2038b4fa722 100644
--- a/doc/source/whatsnew/v2.1.0.rst
+++ b/doc/source/whatsnew/v2.1.0.rst
@@ -87,6 +87,7 @@ Other enhancements
 - :meth:`DataFrame.applymap` now uses the :meth:`~api.extensions.ExtensionArray.map` method of underlying :class:`api.extensions.ExtensionArray` instances (:issue:`52219`)
 - :meth:`arrays.SparseArray.map` now supports ``na_action`` (:issue:`52096`).
 - Add dtype of categories to ``repr`` information of :class:`CategoricalDtype` (:issue:`52179`)
+- Adding ``engine_kwargs`` parameter to :meth:`DataFrame.read_excel` (:issue:`52214`)
 - Add :meth:`diff()` and :meth:`round()` for :class:`Index` (:issue:`19708`)
 -
 .. ---------------------------------------------------------------------------

From 50a518138ca0e364a86a00e9871d38f2caad3670 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Thu, 13 Apr 2023 04:21:56 +0300
Subject: [PATCH 17/35] Resolve conflict

---
 doc/source/whatsnew/v2.1.0.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/source/whatsnew/v2.1.0.rst b/doc/source/whatsnew/v2.1.0.rst
index ac2038b4fa722..f85442b3692c1 100644
--- a/doc/source/whatsnew/v2.1.0.rst
+++ b/doc/source/whatsnew/v2.1.0.rst
@@ -87,8 +87,8 @@ Other enhancements
 - :meth:`DataFrame.applymap` now uses the :meth:`~api.extensions.ExtensionArray.map` method of underlying :class:`api.extensions.ExtensionArray` instances (:issue:`52219`)
 - :meth:`arrays.SparseArray.map` now supports ``na_action`` (:issue:`52096`).
 - Add dtype of categories to ``repr`` information of :class:`CategoricalDtype` (:issue:`52179`)
-- Adding ``engine_kwargs`` parameter to :meth:`DataFrame.read_excel` (:issue:`52214`)
 - Add :meth:`diff()` and :meth:`round()` for :class:`Index` (:issue:`19708`)
+- Adding ``engine_kwargs`` parameter to :meth:`DataFrame.read_excel` (:issue:`52214`)
 -
 .. ---------------------------------------------------------------------------
 .. _whatsnew_210.notable_bug_fixes:

From 06b8ff8bb42f6e8f1ccd615bffb771789a1ee7b1 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Sun, 9 Apr 2023 20:25:50 +0000
Subject: [PATCH 18/35] Add diff() and round() methods for Index and a test for
 each

---
 pandas/core/indexes/base.py       | 35 +++++++++++++++++++++++++++++++
 pandas/tests/indexes/test_base.py | 18 ++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 0a56fa4d031d6..78005419e854e 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6758,6 +6758,41 @@ def infer_objects(self, copy: bool = True) -> Index:
             result._references.add_index_reference(result)
         return result
 
+    def diff(self, periods=1):
+        """
+        Computes the difference between consecutive values in the Index object.
+        If periods is greater than 1, computes the difference between values that
+        are `periods` number of positions apart.
+
+        Parameters:
+            periods (int): The number of positions between the current and previous
+            value to compute the difference with. Default is 1.
+
+        Returns:
+        Index
+            A new Index object with the computed differences.
+
+        """
+        return Index(self.to_series().diff(periods))
+
+    def round(self, decimals=0):
+        """
+        Round each value in the Index to the given number of decimals.
+
+        Parameters
+        ----------
+        decimals : int, optional
+            Number of decimal places to round to. If decimals is negative,
+            it specifies the number of positions to the left of the decimal point.
+
+        Returns
+        -------
+        Index
+            A new Index with the rounded values.
+
+        """
+        return Index(self.to_series().round(decimals))
+
     # --------------------------------------------------------------------
     # Generated Arithmetic, Comparison, and Unary Methods
 
diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index e681223933abb..a69a50fc82bc6 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -1270,6 +1270,24 @@ def test_sortlevel_na_position(self):
         expected = Index([np.nan, 1])
         tm.assert_index_equal(result, expected)
 
+    def test_index_diff(self):
+        # GH#19708
+        idx = Index([10, 20, 30, 40, 50])
+        diffs = idx.diff()
+        diffs_period2 = idx.diff(periods=2)
+
+        assert diffs.equals(Index([np.nan, 10, 10, 10, 10]))
+        assert diffs_period2.equals(Index([np.nan, np.nan, 20, 20, 20]))
+
+    def test_index_round(self):
+        # GH#19708
+        idx = Index([1.234, 2.345, 3.456])
+        rounded = idx.round()
+        rounded_2decimals = idx.round(2)
+
+        assert rounded.equals(Index([1, 2, 3]))
+        assert rounded_2decimals.equals(Index([1.23, 2.35, 3.46]))
+
 
 class TestMixedIntIndex(Base):
     # Mostly the tests from common.py for which the results differ

From bedf16d9ebee18fed390545b5c191fe84750630c Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Sun, 9 Apr 2023 21:07:13 +0000
Subject: [PATCH 19/35] Fix code style

---
 pandas/core/indexes/base.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 78005419e854e..e6fffc5f8da77 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6758,7 +6758,7 @@ def infer_objects(self, copy: bool = True) -> Index:
             result._references.add_index_reference(result)
         return result
 
-    def diff(self, periods=1):
+    def diff(self, periods: int=1):
         """
         Computes the difference between consecutive values in the Index object.
         If periods is greater than 1, computes the difference between values that
@@ -6775,7 +6775,7 @@ def diff(self, periods=1):
         """
         return Index(self.to_series().diff(periods))
 
-    def round(self, decimals=0):
+    def round(self, decimals: int=0):
         """
         Round each value in the Index to the given number of decimals.
 

From 61086a645246d1b93c528c17baafefffad0071d2 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Sun, 9 Apr 2023 21:15:17 +0000
Subject: [PATCH 20/35] Fix code style

---
 pandas/core/indexes/base.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index e6fffc5f8da77..a9fe8a05c59c7 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6758,7 +6758,7 @@ def infer_objects(self, copy: bool = True) -> Index:
             result._references.add_index_reference(result)
         return result
 
-    def diff(self, periods: int=1):
+    def diff(self, periods: int = 1):
         """
         Computes the difference between consecutive values in the Index object.
         If periods is greater than 1, computes the difference between values that
@@ -6775,7 +6775,7 @@ def diff(self, periods: int=1):
         """
         return Index(self.to_series().diff(periods))
 
-    def round(self, decimals: int=0):
+    def round(self, decimals: int = 0):
         """
         Round each value in the Index to the given number of decimals.
 

From 364ae36d6235786784dff39ee6c0c7171b8c5d96 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Mon, 10 Apr 2023 23:34:29 +0000
Subject: [PATCH 21/35] Add pytest.mark.parametrize and fix docstring style

---
 pandas/core/indexes/base.py       |  1 +
 pandas/tests/indexes/test_base.py | 32 +++++++++++++++++++++----------
 2 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index a9fe8a05c59c7..270286177bca0 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6761,6 +6761,7 @@ def infer_objects(self, copy: bool = True) -> Index:
     def diff(self, periods: int = 1):
         """
         Computes the difference between consecutive values in the Index object.
+
         If periods is greater than 1, computes the difference between values that
         are `periods` number of positions apart.
 
diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index a69a50fc82bc6..ffa0928c802bf 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -1270,23 +1270,35 @@ def test_sortlevel_na_position(self):
         expected = Index([np.nan, 1])
         tm.assert_index_equal(result, expected)
 
-    def test_index_diff(self):
+    @pytest.mark.parametrize(
+        "periods, expected",
+        [
+            (1, Index([np.nan, 10, 10, 10, 10])),
+            (2, Index([np.nan, np.nan, 20, 20, 20])),
+            (3, Index([np.nan, np.nan, np.nan, 30, 30])),
+        ],
+    )
+    def test_index_diff(self, periods, expected):
         # GH#19708
         idx = Index([10, 20, 30, 40, 50])
-        diffs = idx.diff()
-        diffs_period2 = idx.diff(periods=2)
+        result = idx.diff()
 
-        assert diffs.equals(Index([np.nan, 10, 10, 10, 10]))
-        assert diffs_period2.equals(Index([np.nan, np.nan, 20, 20, 20]))
+        tm.assert_index_equal(result, expected)
 
-    def test_index_round(self):
+    @pytest.mark.parametrize(
+        "decimals, expected",
+        [
+            (0, Index([1, 2, 3])),
+            (1, Index([1.2, 2.3, 3.5])),
+            (2, Index([1.23, 2.35, 3.46])),
+        ],
+    )
+    def test_index_round(self, decimals, expected):
         # GH#19708
         idx = Index([1.234, 2.345, 3.456])
-        rounded = idx.round()
-        rounded_2decimals = idx.round(2)
+        result = idx.round()
 
-        assert rounded.equals(Index([1, 2, 3]))
-        assert rounded_2decimals.equals(Index([1.23, 2.35, 3.46]))
+        tm.assert_index_equal(result, expected)
 
 
 class TestMixedIntIndex(Base):

From 3f5697349ab742998e66fafd0f62c99631e739e2 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Mon, 10 Apr 2023 23:51:30 +0000
Subject: [PATCH 22/35] Move Index call

---
 pandas/tests/indexes/test_base.py | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index ffa0928c802bf..fb60a1be176ed 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -1271,32 +1271,34 @@ def test_sortlevel_na_position(self):
         tm.assert_index_equal(result, expected)
 
     @pytest.mark.parametrize(
-        "periods, expected",
+        "periods, expected_results",
         [
-            (1, Index([np.nan, 10, 10, 10, 10])),
-            (2, Index([np.nan, np.nan, 20, 20, 20])),
-            (3, Index([np.nan, np.nan, np.nan, 30, 30])),
+            (1, [np.nan, 10, 10, 10, 10]),
+            (2, [np.nan, np.nan, 20, 20, 20]),
+            (3, [np.nan, np.nan, np.nan, 30, 30]),
         ],
     )
-    def test_index_diff(self, periods, expected):
+    def test_index_diff(self, periods, expected_results):
         # GH#19708
         idx = Index([10, 20, 30, 40, 50])
         result = idx.diff()
+        expected = Index(expected_results)
 
         tm.assert_index_equal(result, expected)
 
     @pytest.mark.parametrize(
-        "decimals, expected",
+        "decimals, expected_results",
         [
-            (0, Index([1, 2, 3])),
-            (1, Index([1.2, 2.3, 3.5])),
-            (2, Index([1.23, 2.35, 3.46])),
+            (0, [1, 2, 3]),
+            (1, [1.2, 2.3, 3.5]),
+            (2, [1.23, 2.35, 3.46]),
         ],
     )
-    def test_index_round(self, decimals, expected):
+    def test_index_round(self, decimals, expected_results):
         # GH#19708
         idx = Index([1.234, 2.345, 3.456])
         result = idx.round()
+        expected = Index(expected_results)
 
         tm.assert_index_equal(result, expected)
 

From d96196db267638b49fd0adbae6a6373dea9598b4 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 12:04:41 +0000
Subject: [PATCH 23/35] Fix diff() and round() call

---
 pandas/tests/indexes/test_base.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index fb60a1be176ed..790534f35abd5 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -1281,7 +1281,7 @@ def test_sortlevel_na_position(self):
     def test_index_diff(self, periods, expected_results):
         # GH#19708
         idx = Index([10, 20, 30, 40, 50])
-        result = idx.diff()
+        result = idx.diff(periods)
         expected = Index(expected_results)
 
         tm.assert_index_equal(result, expected)
@@ -1297,7 +1297,7 @@ def test_index_diff(self, periods, expected_results):
     def test_index_round(self, decimals, expected_results):
         # GH#19708
         idx = Index([1.234, 2.345, 3.456])
-        result = idx.round()
+        result = idx.round(decimals)
         expected = Index(expected_results)
 
         tm.assert_index_equal(result, expected)

From 5a653346c5358404c0320a333ffeddaeed2d3876 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 12:38:28 +0000
Subject: [PATCH 24/35] Change Index to float

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

diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index 790534f35abd5..db317a819c520 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -1289,7 +1289,7 @@ def test_index_diff(self, periods, expected_results):
     @pytest.mark.parametrize(
         "decimals, expected_results",
         [
-            (0, [1, 2, 3]),
+            (0, [1.0, 2.0, 3.0]),
             (1, [1.2, 2.3, 3.5]),
             (2, [1.23, 2.35, 3.46]),
         ],

From db307574ac94d17deead6405fb9b6c3241ed795b Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 14:13:33 +0000
Subject: [PATCH 25/35] Fix docstring style

---
 pandas/core/indexes/base.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 270286177bca0..864cea52603b6 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6770,6 +6770,7 @@ def diff(self, periods: int = 1):
             value to compute the difference with. Default is 1.
 
         Returns:
+        -------
         Index
             A new Index object with the computed differences.
 

From 2b105e9f810a15a8c5d02f4ab82bb1980b9f4f08 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 15:46:08 +0000
Subject: [PATCH 26/35] Fix docstring style

---
 pandas/core/indexes/base.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 864cea52603b6..3c8a164c88429 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6765,11 +6765,13 @@ def diff(self, periods: int = 1):
         If periods is greater than 1, computes the difference between values that
         are `periods` number of positions apart.
 
-        Parameters:
-            periods (int): The number of positions between the current and previous
+        Parameters
+        ----------
+        periods : int, optional 
+            The number of positions between the current and previous
             value to compute the difference with. Default is 1.
 
-        Returns:
+        Returns
         -------
         Index
             A new Index object with the computed differences.

From 47e9866cad8e110141fd65c69271d5d669312a3a Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 15:56:34 +0000
Subject: [PATCH 27/35] Fix pre-commit errors

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

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 3c8a164c88429..32c7b9aa36d1e 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6767,7 +6767,7 @@ def diff(self, periods: int = 1):
 
         Parameters
         ----------
-        periods : int, optional 
+        periods : int, optional
             The number of positions between the current and previous
             value to compute the difference with. Default is 1.
 

From 69d32f7e1f64c9d6d7cb903038776c9276e7822a Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 20:49:07 +0000
Subject: [PATCH 28/35] Add example section in docstring and change return
 statement

---
 pandas/core/indexes/base.py | 39 +++++++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 32c7b9aa36d1e..d45cc326b4ff0 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6776,8 +6776,27 @@ def diff(self, periods: int = 1):
         Index
             A new Index object with the computed differences.
 
+        Example
+        -------
+        >>> import pandas as pd
+        >>> idx = pd.Index([10, 20, 30, 40, 50])
+        >>> diff_idx = idx.diff()
+        >>> print(diff_idx)
+        Float64Index([nan, 10.0, 10.0, 10.0, 10.0], dtype='float64')
+
+        This example creates a new `Index` object `idx` with values
+        `[10, 20, 30, 40, 50]`.
+
+        The `diff` method is then used to compute the difference between
+        consecutive values in the `Index` object.
+
+        The resulting `diff_idx` object has the values `[nan, 10.0, 10.0, 10.0, 10.0]`.
+
+        Note that the first value is `nan` since there is no previous value to compute
+        the difference with.
+
         """
-        return Index(self.to_series().diff(periods))
+        return self._constructor(self.to_series().diff(periods))
 
     def round(self, decimals: int = 0):
         """
@@ -6794,8 +6813,24 @@ def round(self, decimals: int = 0):
         Index
             A new Index with the rounded values.
 
+        Example
+        -------
+        >>> import pandas as pd
+        >>> idx = pd.Index([10.1234, 20.5678, 30.9123, 40.4567, 50.7890])
+        >>> rounded_idx = idx.round(decimals=2)
+        >>> print(rounded_idx)
+        Float64Index([10.12, 20.57, 30.91, 40.46, 50.79], dtype='float64')
+
+        This example creates a new `Index` object `idx` with values
+        `[10.1234, 20.5678, 30.9123, 40.4567, 50.7890]`.
+
+        The `round` method is then used to round each value to two decimal places.
+
+        The resulting `rounded_idx` object has the values
+        `[10.12, 20.57, 30.91, 40.46, 50.79]`.
+
         """
-        return Index(self.to_series().round(decimals))
+        return self._constructor(self.to_series().round(decimals))
 
     # --------------------------------------------------------------------
     # Generated Arithmetic, Comparison, and Unary Methods

From 5475c37fa27a088eaa3a8bc4812913aa66c77848 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 21:30:51 +0000
Subject: [PATCH 29/35] Fix docstring example section

---
 pandas/core/indexes/base.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index d45cc326b4ff0..fa05bd0474a04 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6782,7 +6782,7 @@ def diff(self, periods: int = 1):
         >>> idx = pd.Index([10, 20, 30, 40, 50])
         >>> diff_idx = idx.diff()
         >>> print(diff_idx)
-        Float64Index([nan, 10.0, 10.0, 10.0, 10.0], dtype='float64')
+        Index([nan, 10.0, 10.0, 10.0, 10.0], dtype='float64')
 
         This example creates a new `Index` object `idx` with values
         `[10, 20, 30, 40, 50]`.
@@ -6819,7 +6819,7 @@ def round(self, decimals: int = 0):
         >>> idx = pd.Index([10.1234, 20.5678, 30.9123, 40.4567, 50.7890])
         >>> rounded_idx = idx.round(decimals=2)
         >>> print(rounded_idx)
-        Float64Index([10.12, 20.57, 30.91, 40.46, 50.79], dtype='float64')
+        Index([10.12, 20.57, 30.91, 40.46, 50.79], dtype='float64')
 
         This example creates a new `Index` object `idx` with values
         `[10.1234, 20.5678, 30.9123, 40.4567, 50.7890]`.

From 960540c47e20c61849951b5b647a391ea0471a2a Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Tue, 11 Apr 2023 23:57:12 +0000
Subject: [PATCH 30/35] Fix docstring

---
 pandas/core/indexes/base.py | 33 ++++++---------------------------
 1 file changed, 6 insertions(+), 27 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index fa05bd0474a04..60b4bfd65c39d 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6776,25 +6776,13 @@ def diff(self, periods: int = 1):
         Index
             A new Index object with the computed differences.
 
-        Example
-        -------
+        Examples
+        --------
         >>> import pandas as pd
         >>> idx = pd.Index([10, 20, 30, 40, 50])
-        >>> diff_idx = idx.diff()
-        >>> print(diff_idx)
+        >>> idx.diff()
         Index([nan, 10.0, 10.0, 10.0, 10.0], dtype='float64')
 
-        This example creates a new `Index` object `idx` with values
-        `[10, 20, 30, 40, 50]`.
-
-        The `diff` method is then used to compute the difference between
-        consecutive values in the `Index` object.
-
-        The resulting `diff_idx` object has the values `[nan, 10.0, 10.0, 10.0, 10.0]`.
-
-        Note that the first value is `nan` since there is no previous value to compute
-        the difference with.
-
         """
         return self._constructor(self.to_series().diff(periods))
 
@@ -6813,22 +6801,13 @@ def round(self, decimals: int = 0):
         Index
             A new Index with the rounded values.
 
-        Example
-        -------
+        Examples
+        --------
         >>> import pandas as pd
         >>> idx = pd.Index([10.1234, 20.5678, 30.9123, 40.4567, 50.7890])
-        >>> rounded_idx = idx.round(decimals=2)
-        >>> print(rounded_idx)
+        >>> idx.round(decimals=2)
         Index([10.12, 20.57, 30.91, 40.46, 50.79], dtype='float64')
 
-        This example creates a new `Index` object `idx` with values
-        `[10.1234, 20.5678, 30.9123, 40.4567, 50.7890]`.
-
-        The `round` method is then used to round each value to two decimal places.
-
-        The resulting `rounded_idx` object has the values
-        `[10.12, 20.57, 30.91, 40.46, 50.79]`.
-
         """
         return self._constructor(self.to_series().round(decimals))
 

From e79323f430702246b5116fe794bc013bf9ca23dd Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Thu, 13 Apr 2023 03:39:50 +0300
Subject: [PATCH 31/35] Add whatsnew in v2.1.0.rst

---
 doc/source/whatsnew/v2.1.0.rst | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/doc/source/whatsnew/v2.1.0.rst b/doc/source/whatsnew/v2.1.0.rst
index 9b5cba1e1ee05..fd4d279aee76c 100644
--- a/doc/source/whatsnew/v2.1.0.rst
+++ b/doc/source/whatsnew/v2.1.0.rst
@@ -67,6 +67,40 @@ Also, note that :meth:`Categorical.map` implicitly has had its ``na_action`` set
 This has been deprecated and will :meth:`Categorical.map` in the future change the default
 to ``na_action=None``, like for all the other array types.
 
+.. _whatsnew_210.enhancements.enhancement3:
+
+Index now has diff() and round() methods
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The :class:`Index` object in Pandas version 2.1.0 has two new methods: :meth:`diff()` and :meth:`round()`. 
+These methods are useful for performing computations on the values in an :class:`Index` object (:issue:`19708`).
+
+The :meth:`diff()` method computes the difference between consecutive values in the index. 
+If the periods parameter is greater than 1, it computes the difference between values 
+that are periods number of positions apart.
+
+For example:
+
+.. code-block:: python
+  
+    import pandas as pd
+
+    idx = pd.Index([10, 20, 30, 40, 50])
+    print(idx.diff())  # Output: [nan, 10.0, 10.0, 10.0, 10.0]
+
+The :meth:`round()` method rounds each value in the index to the given number of decimals.
+
+For example:
+
+.. code-block:: python
+
+    import pandas as pd
+
+    idx = pd.Index([10.1234, 20.5678, 30.9123, 40.4567, 50.7890])
+    print(idx.round(decimals=2))  # Output: [10.12, 20.57, 30.91, 40.46, 50.79]
+    
+We hope these new methods enhance your experience with Pandas!
+
 .. _whatsnew_210.enhancements.other:
 
 Other enhancements

From cea737a5125781565d885b2ee913c75f91aacbc2 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Thu, 13 Apr 2023 04:08:31 +0300
Subject: [PATCH 32/35] Fix whatsnew entry

---
 doc/source/whatsnew/v2.1.0.rst | 35 ----------------------------------
 1 file changed, 35 deletions(-)

diff --git a/doc/source/whatsnew/v2.1.0.rst b/doc/source/whatsnew/v2.1.0.rst
index fd4d279aee76c..7b15aa9e0aaaf 100644
--- a/doc/source/whatsnew/v2.1.0.rst
+++ b/doc/source/whatsnew/v2.1.0.rst
@@ -67,40 +67,6 @@ Also, note that :meth:`Categorical.map` implicitly has had its ``na_action`` set
 This has been deprecated and will :meth:`Categorical.map` in the future change the default
 to ``na_action=None``, like for all the other array types.
 
-.. _whatsnew_210.enhancements.enhancement3:
-
-Index now has diff() and round() methods
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-The :class:`Index` object in Pandas version 2.1.0 has two new methods: :meth:`diff()` and :meth:`round()`. 
-These methods are useful for performing computations on the values in an :class:`Index` object (:issue:`19708`).
-
-The :meth:`diff()` method computes the difference between consecutive values in the index. 
-If the periods parameter is greater than 1, it computes the difference between values 
-that are periods number of positions apart.
-
-For example:
-
-.. code-block:: python
-  
-    import pandas as pd
-
-    idx = pd.Index([10, 20, 30, 40, 50])
-    print(idx.diff())  # Output: [nan, 10.0, 10.0, 10.0, 10.0]
-
-The :meth:`round()` method rounds each value in the index to the given number of decimals.
-
-For example:
-
-.. code-block:: python
-
-    import pandas as pd
-
-    idx = pd.Index([10.1234, 20.5678, 30.9123, 40.4567, 50.7890])
-    print(idx.round(decimals=2))  # Output: [10.12, 20.57, 30.91, 40.46, 50.79]
-    
-We hope these new methods enhance your experience with Pandas!
-
 .. _whatsnew_210.enhancements.other:
 
 Other enhancements
@@ -123,7 +89,6 @@ Other enhancements
 - Add dtype of categories to ``repr`` information of :class:`CategoricalDtype` (:issue:`52179`)
 - Adding ``engine_kwargs`` parameter to :meth:`DataFrame.read_excel` (:issue:`52214`)
 -
-
 .. ---------------------------------------------------------------------------
 .. _whatsnew_210.notable_bug_fixes:
 

From 600d46ba1b3f7b4666052616447096a80dae5a8e Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Thu, 13 Apr 2023 13:59:05 +0300
Subject: [PATCH 33/35] Add whatsnew entry

---
 doc/source/whatsnew/v2.1.0.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/source/whatsnew/v2.1.0.rst b/doc/source/whatsnew/v2.1.0.rst
index 7b15aa9e0aaaf..ccc728ccfc211 100644
--- a/doc/source/whatsnew/v2.1.0.rst
+++ b/doc/source/whatsnew/v2.1.0.rst
@@ -88,6 +88,7 @@ Other enhancements
 - :meth:`arrays.SparseArray.map` now supports ``na_action`` (:issue:`52096`).
 - Add dtype of categories to ``repr`` information of :class:`CategoricalDtype` (:issue:`52179`)
 - Adding ``engine_kwargs`` parameter to :meth:`DataFrame.read_excel` (:issue:`52214`)
+- Add :meth:`diff()` and :meth:`round()` for :class:`Index` (:issue:`19708`)
 -
 .. ---------------------------------------------------------------------------
 .. _whatsnew_210.notable_bug_fixes:

From 431c4b25fad2259e35d4932db6b5ee6171e92ba1 Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Thu, 13 Apr 2023 14:05:35 +0300
Subject: [PATCH 34/35] Fix whatsnew entry

---
 doc/source/whatsnew/v2.1.0.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/source/whatsnew/v2.1.0.rst b/doc/source/whatsnew/v2.1.0.rst
index ccc728ccfc211..c7c7051914cc8 100644
--- a/doc/source/whatsnew/v2.1.0.rst
+++ b/doc/source/whatsnew/v2.1.0.rst
@@ -86,9 +86,9 @@ Other enhancements
 - Improved error message when creating a DataFrame with empty data (0 rows), no index and an incorrect number of columns. (:issue:`52084`)
 - :meth:`DataFrame.applymap` now uses the :meth:`~api.extensions.ExtensionArray.map` method of underlying :class:`api.extensions.ExtensionArray` instances (:issue:`52219`)
 - :meth:`arrays.SparseArray.map` now supports ``na_action`` (:issue:`52096`).
+- Add :meth:`diff()` and :meth:`round()` for :class:`Index` (:issue:`19708`)
 - Add dtype of categories to ``repr`` information of :class:`CategoricalDtype` (:issue:`52179`)
 - Adding ``engine_kwargs`` parameter to :meth:`DataFrame.read_excel` (:issue:`52214`)
-- Add :meth:`diff()` and :meth:`round()` for :class:`Index` (:issue:`19708`)
 -
 .. ---------------------------------------------------------------------------
 .. _whatsnew_210.notable_bug_fixes:

From a428bc8ae8937009356314ee8c2507eb744d713a Mon Sep 17 00:00:00 2001
From: GrammatikakisDimitris <t8200035@aueb.gr>
Date: Sat, 15 Apr 2023 13:22:20 +0300
Subject: [PATCH 35/35] Add blank line in v2.1.0.rst

---
 doc/source/whatsnew/v2.1.0.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/source/whatsnew/v2.1.0.rst b/doc/source/whatsnew/v2.1.0.rst
index f80cd7d8e31c1..f32598e72685e 100644
--- a/doc/source/whatsnew/v2.1.0.rst
+++ b/doc/source/whatsnew/v2.1.0.rst
@@ -91,6 +91,7 @@ Other enhancements
 - Let :meth:`DataFrame.to_feather` accept a non-default :class:`Index` and non-string column names (:issue:`51787`)
 - Performance improvement in :func:`read_csv` (:issue:`52632`) with ``engine="c"``
 -
+
 .. ---------------------------------------------------------------------------
 .. _whatsnew_210.notable_bug_fixes: