merged is_month_start and is_month_end docstrings

pandas/core/arrays/datetimes.py

@@ -998,77 +998,62 @@ def date(self):
         'dim',
         "The number of days in the month")
     daysinmonth = days_in_month
-    _is_month_start_doc = """
-        Indicates whether the date is the first day of the month.
+    _is_month_doc = """
+        Indicates whether the date is the {first_or_last} day of the month.
 
         Returns
         -------
-        Series of bool
-            Series of boolean values indicating whether the date is the first
-            day of the month.
+        Series or array
+            For Series, returns a Series with bool.
+            For DatetimeIndex, returns a bool array.
 
         See Also
         --------
-        is_month_end : Return a boolean indicating whether the date is
-            the last day of the month.
+        is_month_{end_or_start} : Return a boolean indicating whether the date
+            is the {last_or_first} day of the month.
 
         Examples
         --------
+        This method is available on Series with datetime values under
+        the ``.dt`` accessor, and directly on DatetimeIndex.
+
         >>> s = pd.Series(pd.date_range("2018-02-27", periods=3))
         >>> s
         0   2018-02-27
         1   2018-02-28
         2   2018-03-01
         dtype: datetime64[ns]
-        >>> s.dt.is_month_start
-        0    False
-        1    False
-        2    True
+        >>> s.dt.is_month_{start_or_end}
+        0    {FT[0]}
+        1    {FT[1]}
+        2    {FT[2]}
         dtype: bool
+
+        >>> idx = pd.date_range("2018-02-27", periods=3)
+        >>> idx.is_month_{start_or_end}
+        array([{FT[3]}, {FT[4]}, {FT[5]}])
     """
     is_month_start = _field_accessor(
         'is_month_start',
         'is_month_start',
-        _is_month_start_doc)
+        _is_month_doc.format(
+            first_or_last='first',
+            start_or_end='start',
+            FT=[False, False, True, False, False, True],
+            end_or_start='end',
+            last_or_first='last'
+        ))
 
     is_month_end = _field_accessor(
         'is_month_end',
         'is_month_end',
-        """
-        Indicator for whether the date is the last day of the month.
-
-        Returns
-        -------
-        Series or array
-            For Series, returns a Series with boolean values. For
-            DatetimeIndex, returns a boolean array.
-
-        See Also
-        --------
-        is_month_start : Indicator for whether the date is the first day
-            of the month.
-
-        Examples
-        --------
-        This method is available on Series with datetime values under
-        the ``.dt`` accessor, and directly on DatetimeIndex.
-
-        >>> dates = pd.Series(pd.date_range("2018-02-27", periods=3))
-        >>> dates
-        0   2018-02-27
-        1   2018-02-28
-        2   2018-03-01
-        dtype: datetime64[ns]
-        >>> dates.dt.is_month_end
-        0    False
-        1    True
-        2    False
-        dtype: bool
-
-        >>> idx = pd.date_range("2018-02-27", periods=3)
-        >>> idx.is_month_end
-        array([False,  True, False], dtype=bool)
-        """)
+        _is_month_doc.format(
+            first_or_last='last',
+            start_or_end='end',
+            FT=[False, True, False, False, True, False],
+            end_or_start='start',
+            last_or_first='first'
+        ))
     is_quarter_start = _field_accessor(
         'is_quarter_start',
         'is_quarter_start',