DOC: Fixing EX01 - Added examples (pandas-dev#53575)

Added examples

Author: DeaMariaLeon

ci/code_checks.sh

@@ -263,15 +263,7 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
         pandas.core.window.ewm.ExponentialMovingWindow.cov \
         pandas.api.indexers.BaseIndexer \
         pandas.api.indexers.VariableOffsetWindowIndexer \
-        pandas.core.groupby.DataFrameGroupBy.ffill \
-        pandas.core.groupby.DataFrameGroupBy.ohlc \
         pandas.core.groupby.SeriesGroupBy.fillna \
-        pandas.core.groupby.SeriesGroupBy.ffill \
-        pandas.core.groupby.SeriesGroupBy.nunique \
-        pandas.core.groupby.SeriesGroupBy.ohlc \
-        pandas.core.groupby.SeriesGroupBy.hist \
-        pandas.core.groupby.DataFrameGroupBy.plot \
-        pandas.core.groupby.SeriesGroupBy.plot \
         pandas.io.formats.style.Styler \
         pandas.io.formats.style.Styler.from_custom_template \
         pandas.io.formats.style.Styler.set_caption \

pandas/core/groupby/generic.py

@@ -622,6 +622,22 @@ def nunique(self, dropna: bool = True) -> Series | DataFrame:
         -------
         Series
             Number of unique values within each group.
+
+        Examples
+        --------
+
+        >>> lst = ['a', 'a', 'b', 'b']
+        >>> ser = pd.Series([1, 2, 3, 3], index=lst)
+        >>> ser
+        a    1
+        a    2
+        b    3
+        b    3
+        dtype: int64
+        >>> ser.groupby(level=0).nunique()
+        a    2
+        b    1
+        dtype: int64
         """
         ids, _, _ = self.grouper.group_info
 

pandas/core/groupby/groupby.py

@@ -3107,6 +3107,50 @@ def ohlc(self) -> DataFrame:
         -------
         DataFrame
             Open, high, low and close values within each group.
+
+        Examples
+        --------
+
+        For SeriesGroupBy:
+
+        >>> lst = ['SPX', 'CAC', 'SPX', 'CAC', 'SPX', 'CAC', 'SPX', 'CAC',]
+        >>> ser = pd.Series([3.4, 9.0, 7.2, 5.2, 8.8, 9.4, 0.1, 0.5], index=lst)
+        >>> ser
+        SPX     3.4
+        CAC     9.0
+        SPX     7.2
+        CAC     5.2
+        SPX     8.8
+        CAC     9.4
+        SPX     0.1
+        CAC     0.5
+        dtype: float64
+        >>> ser.groupby(level=0).ohlc()
+             open  high  low  close
+        CAC   9.0   9.4  0.5    0.5
+        SPX   3.4   8.8  0.1    0.1
+
+        For DataFrameGroupBy:
+
+        >>> data = {2022: [1.2, 2.3, 8.9, 4.5, 4.4, 3, 2 , 1],
+        ...         2023: [3.4, 9.0, 7.2, 5.2, 8.8, 9.4, 8.2, 1.0]}
+        >>> df = pd.DataFrame(data, index=['SPX', 'CAC', 'SPX', 'CAC',
+        ...                   'SPX', 'CAC', 'SPX', 'CAC'])
+        >>> df
+             2022  2023
+        SPX   1.2   3.4
+        CAC   2.3   9.0
+        SPX   8.9   7.2
+        CAC   4.5   5.2
+        SPX   4.4   8.8
+        CAC   3.0   9.4
+        SPX   2.0   8.2
+        CAC   1.0   1.0
+        >>> df.groupby(level=0).ohlc()
+            2022                 2023
+            open high  low close open high  low close
+        CAC  2.3  4.5  1.0   1.0  9.0  9.4  1.0   1.0
+        SPX  1.2  8.9  1.2   2.0  3.4  8.8  3.4   8.2
         """
         if self.obj.ndim == 1:
             obj = self._selected_obj
@@ -3561,6 +3605,26 @@ def ffill(self, limit: int | None = None):
 
         Examples
         --------
+
+        For SeriesGroupBy:
+
+        >>> key = [0, 0, 1, 1]
+        >>> ser = pd.Series([np.nan, 2, 3, np.nan], index=key)
+        >>> ser
+        0    NaN
+        0    2.0
+        1    3.0
+        1    NaN
+        dtype: float64
+        >>> ser.groupby(level=0).ffill()
+        0    NaN
+        0    2.0
+        1    3.0
+        1    3.0
+        dtype: float64
+
+        For DataFrameGroupBy:
+
         >>> df = pd.DataFrame(
         ...     {
         ...         "key": [0, 0, 1, 1, 1],

pandas/plotting/_core.py

@@ -98,6 +98,16 @@ def hist_series(
     See Also
     --------
     matplotlib.axes.Axes.hist : Plot a histogram using matplotlib.
+
+    Examples
+    --------
+
+    .. plot::
+        :context: close-figs
+
+        >>> lst = ['a', 'a', 'a', 'b', 'b', 'b']
+        >>> ser = pd.Series([1, 2, 2, 4, 6, 6], index=lst)
+        >>> hist = ser.groupby(level=0).hist()
     """
     plot_backend = _get_plot_backend(backend)
     return plot_backend.hist_series(
@@ -778,12 +788,23 @@ class PlotAccessor(PandasObject):
 
     Examples
     --------
+    For SeriesGroupBy:
 
     .. plot::
         :context: close-figs
 
         >>> ser = pd.Series([1, 2, 3, 3])
         >>> plot = ser.plot(kind='hist', title="My plot")
+
+    For DataFrameGroupBy:
+
+    .. plot::
+        :context: close-figs
+
+        >>> df = pd.DataFrame({'length': [1.5, 0.5, 1.2, 0.9, 3],
+        ...                   'width': [0.7, 0.2, 0.15, 0.2, 1.1]},
+        ...                   index=['pig', 'rabbit', 'duck', 'chicken', 'horse'])
+        >>> plot = df.plot()
     """
 
     _common_kinds = ("line", "bar", "barh", "kde", "density", "area", "hist", "box")