DOC: Fix EX01 issues in docstrings

ci/code_checks.sh

@@ -85,8 +85,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
 
     MSG='Partially validate docstrings (EX01)' ;  echo $MSG
     $BASE_DIR/scripts/validate_docstrings.py --format=actions --errors=EX01 --ignore_functions \
-        pandas.Series.__iter__ \
-        pandas.Series.keys \
         pandas.Series.item \
         pandas.Series.pipe \
         pandas.Series.mode \
@@ -533,8 +531,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
         pandas.api.extensions.ExtensionArray.shape \
         pandas.api.extensions.ExtensionArray.tolist \
         pandas.DataFrame.columns \
-        pandas.DataFrame.__iter__ \
-        pandas.DataFrame.keys \
         pandas.DataFrame.iterrows \
         pandas.DataFrame.pipe \
         pandas.DataFrame.backfill \

pandas/core/base.py

@@ -736,6 +736,15 @@ def __iter__(self) -> Iterator:
         Returns
         -------
         iterator
+
+        Examples
+        --------
+        >>> s = pd.Series([1, 2, 3])
+        >>> for x in s:
+        ...     print(x)
+        1
+        2
+        3
         """
         # We are explicitly making element iterators.
         if not isinstance(self._values, np.ndarray):

pandas/core/generic.py

@@ -1900,6 +1900,14 @@ def __iter__(self) -> Iterator:
         -------
         iterator
             Info axis as iterator.
+
+        Examples
+        --------
+        >>> df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})
+        >>> for x in df:
+        ...     print(x)
+        A
+        B
         """
         return iter(self._info_axis)
 
@@ -1914,6 +1922,18 @@ def keys(self) -> Index:
         -------
         Index
             Info axis.
+
+        Examples
+        --------
+        >>> d = pd.DataFrame(data={'A': [1, 2, 3], 'B': [0, 4, 8]},
+        ...                  index=['a', 'b', 'c'])
+        >>> d
+           A  B
+        a  1  0
+        b  2  4
+        c  3  8
+        >>> d.keys()
+        Index(['A', 'B'], dtype='object')
         """
         return self._info_axis
 

pandas/core/series.py

@@ -1822,6 +1822,12 @@ def keys(self) -> Index:
         -------
         Index
             Index of the Series.
+
+        Examples
+        --------
+        >>> s = pd.Series([1, 2, 3], index=[0, 1, 2])
+        >>> s.keys()
+        Index([0, 1, 2], dtype='int64')
         """
         return self.index