DOC: fix EX02 errors in docstrings (#51614)

* DOC: fix EX02 errors in docstrings

* skipping radviz plotting doctest

---------

Co-authored-by: Yaxin Li <[email protected]>

Author: lia2710

ci/code_checks.sh

@@ -567,9 +567,7 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
         pandas.plotting.andrews_curves \
         pandas.plotting.autocorrelation_plot \
         pandas.plotting.lag_plot \
-        pandas.plotting.parallel_coordinates \
-        pandas.plotting.radviz \
-        pandas.tseries.frequencies.to_offset
+        pandas.plotting.parallel_coordinates
     RET=$(($RET + $?)) ; echo $MSG "DONE"
 
 fi

pandas/_libs/tslibs/offsets.pyx

@@ -4109,6 +4109,7 @@ cpdef to_offset(freq):
 
     Examples
     --------
+    >>> from pandas.tseries.frequencies import to_offset
     >>> to_offset("5min")
     <5 * Minutes>
 
@@ -4124,7 +4125,7 @@ cpdef to_offset(freq):
     >>> to_offset(pd.Timedelta(days=1))
     <Day>
 
-    >>> to_offset(Hour())
+    >>> to_offset(pd.offsets.Hour())
     <Hour>
     """
     if freq is None:

pandas/plotting/_misc.py

@@ -246,8 +246,7 @@ def radviz(
         ...         ]
         ...     }
         ... )
-        >>> pd.plotting.radviz(df, 'Category')
-        <AxesSubplot: xlabel='y(t)', ylabel='y(t + 1)'>
+        >>> pd.plotting.radviz(df, 'Category')  # doctest: +SKIP
     """
     plot_backend = _get_plot_backend("matplotlib")
     return plot_backend.radviz(