[SNOW-1458134]: Add support for monotonic checks for Series and Index

CHANGELOG.md

@@ -72,6 +72,8 @@
 - Added support for `Index.is_boolean`, `Index.is_integer`, `Index.is_floating`, `Index.is_numeric`, and `Index.is_object`.
 - Added support for `DatetimeIndex.round`, `DatetimeIndex.floor` and `DatetimeIndex.ceil`.
 - Added support for `Series.dt.days_in_month` and `Series.dt.daysinmonth`.
+- Added support for `Series.is_monotonic_increasing` and `Series.is_monotonic_decreasing`.
+- Added support for `Index.is_monotonic_increasing` and `Index.is_monotonic_decreasing`.
 
 #### Improvements
 

docs/source/modin/supported/index_supported.rst

@@ -20,9 +20,9 @@ Attributes
 +-----------------------------+---------------------------------+----------------------------------------------------+
 | ``values``                  | Y                               |                                                    |
 +-----------------------------+---------------------------------+----------------------------------------------------+
-| ``is_monotonic_increasing`` | N                               |                                                    |
+| ``is_monotonic_increasing`` | Y                               |                                                    |
 +-----------------------------+---------------------------------+----------------------------------------------------+
-| ``is_monotonic_decreasing`` | N                               |                                                    |
+| ``is_monotonic_decreasing`` | Y                               |                                                    |
 +-----------------------------+---------------------------------+----------------------------------------------------+
 | ``is_unique``               | Y                               |                                                    |
 +-----------------------------+---------------------------------+----------------------------------------------------+

docs/source/modin/supported/series_supported.rst

@@ -43,9 +43,9 @@ Attributes
 +-----------------------------+---------------------------------+----------------------------------------------------+
 | ``index``                   | Y                               |                                                    |
 +-----------------------------+---------------------------------+----------------------------------------------------+
-| ``is_monotonic_decreasing`` | N                               |                                                    |
+| ``is_monotonic_decreasing`` | Y                               |                                                    |
 +-----------------------------+---------------------------------+----------------------------------------------------+
-| ``is_monotonic_increasing`` | N                               |                                                    |
+| ``is_monotonic_increasing`` | Y                               |                                                    |
 +-----------------------------+---------------------------------+----------------------------------------------------+
 | ``is_unique``               | Y                               |                                                    |
 +-----------------------------+---------------------------------+----------------------------------------------------+

src/snowflake/snowpark/modin/pandas/series.py

@@ -2481,22 +2481,6 @@ def isnull(self):
         """
         return super().isnull()
 
-    @property
-    def is_monotonic_increasing(self):  # noqa: RT01, D200
-        """
-        Return True if values in the Series are monotonic_increasing.
-        """
-        # TODO: SNOW-1063347: Modin upgrade - modin.pandas.Series functions
-        return self._reduce_dimension(self._query_compiler.is_monotonic_increasing())
-
-    @property
-    def is_monotonic_decreasing(self):  # noqa: RT01, D200
-        """
-        Return True if values in the Series are monotonic_decreasing.
-        """
-        # TODO: SNOW-1063347: Modin upgrade - modin.pandas.Series functions
-        return self._reduce_dimension(self._query_compiler.is_monotonic_decreasing())
-
     @property
     def is_unique(self):  # noqa: RT01, D200
         """

src/snowflake/snowpark/modin/plugin/compiler/snowflake_query_compiler.py

@@ -2272,9 +2272,105 @@ def reindex(
         else:
             return self._reindex_axis_1(labels=labels, **kwargs)
 
+    def is_monotonic_decreasing(self, index: bool) -> "SnowflakeQueryCompiler":
+        """
+        Returns a QueryCompiler containing only a column that checks for monotonically
+        decreasing values.
+
+        Parameters
+        ----------
+        index: bool
+            Whether or not this is called by an `Index` object. If False, it is assumed
+            that this method is called by a `Series` object, and monotonicity is checked
+            for the first data column. If True, monotonicity is checked for the first index
+            column.
+
+        Returns
+        -------
+        SnowflakeQueryCompiler
+            QueryCompiler with column to ascertain whether data is monotonically decreasing.
+        """
+        col_to_check = (
+            self._modin_frame.index_column_snowflake_quoted_identifiers[0]
+            if index
+            else self._modin_frame.data_column_snowflake_quoted_identifiers[0]
+        )
+        (
+            new_qc,
+            _,
+            monotonic_decreasing_snowflake_quoted_identifier,
+        ) = self._add_columns_for_monotonicity_checks(
+            col_to_check=col_to_check, columns_to_add="decreasing"
+        )
+        new_modin_frame = new_qc._modin_frame
+        return SnowflakeQueryCompiler(
+            InternalFrame.create(
+                ordered_dataframe=new_modin_frame.ordered_dataframe.limit(
+                    n=1, sort=False
+                ),
+                data_column_pandas_index_names=new_modin_frame.data_column_pandas_index_names,
+                data_column_pandas_labels=["monotonic_column"],
+                data_column_snowflake_quoted_identifiers=[
+                    monotonic_decreasing_snowflake_quoted_identifier
+                ],
+                index_column_pandas_labels=new_modin_frame.index_column_pandas_labels,
+                index_column_snowflake_quoted_identifiers=new_modin_frame.index_column_snowflake_quoted_identifiers,
+                data_column_types=None,
+                index_column_types=None,
+            )
+        )
+
+    def is_monotonic_increasing(self, index: bool) -> "SnowflakeQueryCompiler":
+        """
+        Returns a QueryCompiler containing only a column that checks for monotonically
+        increasing values.
+
+        Parameters
+        ----------
+        index: bool
+            Whether or not this is called by an `Index` object. If False, it is assumed
+            that this method is called by a `Series` object, and monotonicity is checked
+            for the first data column. If True, monotonicity is checked for the first index
+            column.
+
+        Returns
+        -------
+        SnowflakeQueryCompiler
+            QueryCompiler with column to ascertain whether data is monotonically increasing.
+        """
+        col_to_check = (
+            self._modin_frame.index_column_snowflake_quoted_identifiers[0]
+            if index
+            else self._modin_frame.data_column_snowflake_quoted_identifiers[0]
+        )
+        (
+            new_qc,
+            monotonic_increasing_snowflake_quoted_identifier,
+            _,
+        ) = self._add_columns_for_monotonicity_checks(
+            col_to_check=col_to_check, columns_to_add="increasing"
+        )
+        new_modin_frame = new_qc._modin_frame
+        return SnowflakeQueryCompiler(
+            InternalFrame.create(
+                ordered_dataframe=new_modin_frame.ordered_dataframe.limit(
+                    n=1, sort=False
+                ),
+                data_column_pandas_index_names=new_modin_frame.data_column_pandas_index_names,
+                data_column_pandas_labels=["monotonic_column"],
+                data_column_snowflake_quoted_identifiers=[
+                    monotonic_increasing_snowflake_quoted_identifier
+                ],
+                index_column_pandas_labels=new_modin_frame.index_column_pandas_labels,
+                index_column_snowflake_quoted_identifiers=new_modin_frame.index_column_snowflake_quoted_identifiers,
+                data_column_types=None,
+                index_column_types=None,
+            )
+        )
+
     def _add_columns_for_monotonicity_checks(
-        self, col_to_check: str
-    ) -> tuple["SnowflakeQueryCompiler", str, str]:
+        self, col_to_check: str, columns_to_add: Optional[str] = None
+    ) -> tuple["SnowflakeQueryCompiler", Optional[str], Optional[str]]:
         """
         Adds columns that check for monotonicity (increasing or decreasing) in the
         specified column.
@@ -2283,6 +2379,8 @@ def _add_columns_for_monotonicity_checks(
         ----------
         col_to_check : str
             The Snowflake quoted identifier for the column whose monotonicity to check.
+        columns_to_add : str, optional
+            Whether or not to add all columns, and if not, which columns to add.
 
         Returns
         -------
@@ -2293,36 +2391,45 @@ def _add_columns_for_monotonicity_checks(
         """
         self._raise_not_implemented_error_for_timedelta()
 
+        assert columns_to_add in [
+            None,
+            "increasing",
+            "decreasing",
+        ], "Invalid value passed to function"
         modin_frame = self._modin_frame
         modin_frame = modin_frame.ensure_row_position_column()
         row_position_column = modin_frame.row_position_snowflake_quoted_identifier
+        monotonic_decreasing_snowflake_quoted_id = None
+        monotonic_increasing_snowflake_quoted_id = None
         modin_frame = modin_frame.append_column(
             "_index_lag_col",
             lag(col_to_check).over(Window.order_by(row_position_column)),
         )
         lag_col_snowflake_quoted_id = (
             modin_frame.data_column_snowflake_quoted_identifiers[-1]
         )
-        modin_frame = modin_frame.append_column(
-            "_is_monotonic_decreasing",
-            coalesce(
-                min_(col(col_to_check) < col(lag_col_snowflake_quoted_id)).over(),
-                pandas_lit(False),
-            ),
-        )
-        monotonic_decreasing_snowflake_quoted_id = (
-            modin_frame.data_column_snowflake_quoted_identifiers[-1]
-        )
-        modin_frame = modin_frame.append_column(
-            "_is_monotonic_increasing",
-            coalesce(
-                min_(col(col_to_check) > col(lag_col_snowflake_quoted_id)).over(),
-                pandas_lit(False),
-            ),
-        )
-        monotonic_increasing_snowflake_quoted_id = (
-            modin_frame.data_column_snowflake_quoted_identifiers[-1]
-        )
+        if columns_to_add in [None, "decreasing"]:
+            modin_frame = modin_frame.append_column(
+                "_is_monotonic_decreasing",
+                coalesce(
+                    min_(col(col_to_check) <= col(lag_col_snowflake_quoted_id)).over(),
+                    pandas_lit(False),
+                ),
+            )
+            monotonic_decreasing_snowflake_quoted_id = (
+                modin_frame.data_column_snowflake_quoted_identifiers[-1]
+            )
+        if columns_to_add in [None, "increasing"]:
+            modin_frame = modin_frame.append_column(
+                "_is_monotonic_increasing",
+                coalesce(
+                    min_(col(col_to_check) >= col(lag_col_snowflake_quoted_id)).over(),
+                    pandas_lit(False),
+                ),
+            )
+            monotonic_increasing_snowflake_quoted_id = (
+                modin_frame.data_column_snowflake_quoted_identifiers[-1]
+            )
         data_column_pandas_labels = modin_frame.data_column_pandas_labels
         data_column_snowflake_quoted_identifiers = (
             modin_frame.data_column_snowflake_quoted_identifiers

src/snowflake/snowpark/modin/plugin/docstrings/series.py

@@ -3659,6 +3659,38 @@ def hasnans():
         Return True if there are any NaNs.
         """
 
+    @property
+    def is_monotonic_increasing():
+        """
+        Return boolean if values in the object are monotonically decreasing.
+
+        Examples
+        --------
+        >>> s = pd.Series([3, 2, 2, 1])
+        >>> s.is_monotonic_decreasing
+        True
+
+        >>> s = pd.Series([1, 2, 3])
+        >>> s.is_monotonic_decreasing
+        False
+        """
+
+    @property
+    def is_monotonic_decreasing():
+        """
+        Return boolean if values in the object are monotonically increasing.
+
+        Examples
+        --------
+        >>> s = pd.Series([1, 2, 2])
+        >>> s.is_monotonic_increasing
+        True
+
+        >>> s = pd.Series([3, 2, 1])
+        >>> s.is_monotonic_increasing
+        False
+        """
+
     def isna():
         """
         Detect missing values.
@@ -3719,18 +3751,6 @@ def isnull():
         dtype: bool
         """
 
-    @property
-    def is_monotonic_increasing():
-        """
-        Return True if values in the Series are monotonic_increasing.
-        """
-
-    @property
-    def is_monotonic_decreasing():
-        """
-        Return True if values in the Series are monotonic_decreasing.
-        """
-
     @property
     def is_unique():
         """

src/snowflake/snowpark/modin/plugin/extensions/index.py

@@ -398,7 +398,6 @@ def values(self) -> ArrayLike:
         return self.to_pandas().values
 
     @property
-    @index_not_implemented()
     def is_monotonic_increasing(self) -> None:
         """
         Return a boolean if the values are equal or increasing.
@@ -411,11 +410,23 @@ def is_monotonic_increasing(self) -> None:
         See Also
         --------
         Index.is_monotonic_decreasing : Check if the values are equal or decreasing
+
+        Examples
+        --------
+        >>> pd.Index([1, 2, 3]).is_monotonic_increasing
+        True
+        >>> pd.Index([1, 2, 2]).is_monotonic_increasing
+        True
+        >>> pd.Index([1, 3, 2]).is_monotonic_increasing
+        False
         """
-        # TODO: SNOW-1458134 implement is_monotonic_increasing
+        return (
+            self._query_compiler.is_monotonic_increasing(index=True)
+            .to_pandas()
+            .squeeze()
+        )
 
     @property
-    @index_not_implemented()
     def is_monotonic_decreasing(self) -> None:
         """
         Return a boolean if the values are equal or decreasing.
@@ -428,8 +439,21 @@ def is_monotonic_decreasing(self) -> None:
         See Also
         --------
         Index.is_monotonic_increasing : Check if the values are equal or increasing
+
+        Examples
+        --------
+        >>> pd.Index([3, 2, 1]).is_monotonic_decreasing
+        True
+        >>> pd.Index([3, 2, 2]).is_monotonic_decreasing
+        True
+        >>> pd.Index([3, 1, 2]).is_monotonic_decreasing
+        False
         """
-        # TODO: SNOW-1458134 implement is_monotonic_decreasing
+        return (
+            self._query_compiler.is_monotonic_decreasing(index=True)
+            .to_pandas()
+            .squeeze()
+        )
 
     @property
     def is_unique(self) -> bool:

src/snowflake/snowpark/modin/plugin/extensions/series_overrides.py

@@ -164,3 +164,29 @@ def plot(
 @series_not_implemented()
 def transform(self, func, axis=0, *args, **kwargs):  # noqa: PR01, RT01, D200
     pass  # pragma: no cover
+
+
+@register_series_accessor("is_monotonic_increasing")
+@property
+@snowpark_pandas_telemetry_method_decorator
+def is_monotonic_increasing(self):  # noqa: RT01, D200
+    """
+    Return True if values in the Series are monotonic_increasing.
+    """
+    # TODO: SNOW-1063347: Modin upgrade - modin.pandas.Series functions
+    return self._reduce_dimension(
+        self._query_compiler.is_monotonic_increasing(index=False)
+    )
+
+
+@register_series_accessor("is_monotonic_decreasing")
+@property
+@snowpark_pandas_telemetry_method_decorator
+def is_monotonic_decreasing(self):  # noqa: RT01, D200
+    """
+    Return True if values in the Series are monotonic_decreasing.
+    """
+    # TODO: SNOW-1063347: Modin upgrade - modin.pandas.Series functions
+    return self._reduce_dimension(
+        self._query_compiler.is_monotonic_decreasing(index=False)
+    )