DOC Fixing EX01 - added examples (pandas-dev#53181)

* DOC Fixing EX01 - added examples

* Removed Index.item from code_checks

* Removed #GH13

* Added case for return value=False

* Added False case for is_unique

* Correct docstring

* really minor clarification (there may be multiple groups, so "the group" isnt defined)

---------

Co-authored-by: MarcoGorelli <33491632+MarcoGorelli@users.noreply.github.com>

ci/code_checks.sh

@@ -80,12 +80,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
 
     MSG='Partially validate docstrings (EX01)' ;  echo $MSG
     $BASE_DIR/scripts/validate_docstrings.py --format=actions --errors=EX01 --ignore_functions \
-        pandas.Series.item \
-        pandas.Series.pipe \
-        pandas.Series.mode \
-        pandas.Series.is_unique \
-        pandas.Series.is_monotonic_increasing \
-        pandas.Series.is_monotonic_decreasing \
         pandas.Series.backfill \
         pandas.Series.bfill \
         pandas.Series.ffill \
@@ -319,7 +313,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
         pandas.Index.fillna \
         pandas.Index.dropna \
         pandas.Index.astype \
-        pandas.Index.item \
         pandas.Index.map \
         pandas.Index.ravel \
         pandas.Index.to_list \
@@ -462,8 +455,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
         pandas.core.groupby.SeriesGroupBy.cumsum \
         pandas.core.groupby.SeriesGroupBy.diff \
         pandas.core.groupby.SeriesGroupBy.ffill \
-        pandas.core.groupby.SeriesGroupBy.is_monotonic_increasing \
-        pandas.core.groupby.SeriesGroupBy.is_monotonic_decreasing \
         pandas.core.groupby.SeriesGroupBy.max \
         pandas.core.groupby.SeriesGroupBy.median \
         pandas.core.groupby.SeriesGroupBy.min \

pandas/core/base.py

@@ -357,12 +357,24 @@ def item(self):
         Returns
         -------
         scalar
-            The first element of Series.
+            The first element of Series or Index.
 
         Raises
         ------
         ValueError
-            If the data is not length-1.
+            If the data is not length = 1.
+
+        Examples
+        --------
+        >>> s = pd.Series([1])
+        >>> s.item()
+        1
+
+        For an index:
+
+        >>> s = pd.Series([1], index=['a'])
+        >>> s.index.item()
+        'a'
         """
         if len(self) == 1:
             return next(iter(self))
@@ -965,6 +977,16 @@ def is_unique(self) -> bool:
         Returns
         -------
         bool
+
+        Examples
+        --------
+        >>> s = pd.Series([1, 2, 3])
+        >>> s.is_unique
+        True
+
+        >>> s = pd.Series([1, 2, 3, 1])
+        >>> s.is_unique
+        False
         """
         return self.nunique(dropna=False) == len(self)
 
@@ -976,6 +998,16 @@ def is_monotonic_increasing(self) -> bool:
         Returns
         -------
         bool
+
+        Examples
+        --------
+        >>> s = pd.Series([1, 2, 2])
+        >>> s.is_monotonic_increasing
+        True
+
+        >>> s = pd.Series([3, 2, 1])
+        >>> s.is_monotonic_increasing
+        False
         """
         from pandas import Index
 
@@ -989,6 +1021,16 @@ def is_monotonic_decreasing(self) -> bool:
         Returns
         -------
         bool
+
+        Examples
+        --------
+        >>> s = pd.Series([3, 2, 2, 1])
+        >>> s.is_monotonic_decreasing
+        True
+
+        >>> s = pd.Series([1, 2, 3])
+        >>> s.is_monotonic_decreasing
+        False
         """
         from pandas import Index
 

pandas/core/groupby/generic.py

@@ -1170,13 +1170,41 @@ def cov(
         return result
 
     @property
-    @doc(Series.is_monotonic_increasing.__doc__)
     def is_monotonic_increasing(self) -> Series:
+        """
+        Return whether each group's values are monotonically increasing.
+
+        Returns
+        -------
+        Series
+
+        Examples
+        --------
+        >>> s = pd.Series([2, 1, 3, 4], index=['Falcon', 'Falcon', 'Parrot', 'Parrot'])
+        >>> s.groupby(level=0).is_monotonic_increasing
+        Falcon    False
+        Parrot     True
+        dtype: bool
+        """
         return self.apply(lambda ser: ser.is_monotonic_increasing)
 
     @property
-    @doc(Series.is_monotonic_decreasing.__doc__)
     def is_monotonic_decreasing(self) -> Series:
+        """
+        Return whether each group's values are monotonically decreasing.
+
+        Returns
+        -------
+        Series
+
+        Examples
+        --------
+        >>> s = pd.Series([2, 1, 3, 4], index=['Falcon', 'Falcon', 'Parrot', 'Parrot'])
+        >>> s.groupby(level=0).is_monotonic_decreasing
+        Falcon     True
+        Parrot    False
+        dtype: bool
+        """
         return self.apply(lambda ser: ser.is_monotonic_decreasing)
 
     @doc(Series.hist.__doc__)

pandas/core/series.py

@@ -2085,6 +2085,32 @@ def mode(self, dropna: bool = True) -> Series:
         -------
         Series
             Modes of the Series in sorted order.
+
+        Examples
+        --------
+        >>> s = pd.Series([2, 4, 2, 2, 4, None])
+        >>> s.mode()
+        0    2.0
+        dtype: float64
+
+        More than one mode:
+
+        >>> s = pd.Series([2, 4, 8, 2, 4, None])
+        >>> s.mode()
+        0    2.0
+        1    4.0
+        dtype: float64
+
+        With and without considering null value:
+
+        >>> s = pd.Series([2, 4, None, None, 4, None])
+        >>> s.mode(dropna=False)
+        0   NaN
+        dtype: float64
+        >>> s = pd.Series([2, 4, None, None, 4, None])
+        >>> s.mode()
+        0    4.0
+        dtype: float64
         """
         # TODO: Add option for bins like value_counts()
         values = self._values