DOC: fixing GL08 errors for pandas.IntervalIndex.left, pandas.IntervalIndex.mid and pandas.IntervalIndex.length

ci/code_checks.sh

@@ -150,9 +150,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
         pandas.Index.empty\
         pandas.Index.names\
         pandas.Index.view\
-        pandas.IntervalIndex.left\
-        pandas.IntervalIndex.length\
-        pandas.IntervalIndex.mid\
         pandas.IntervalIndex.right\
         pandas.MultiIndex.codes\
         pandas.Period.freq\

pandas/core/indexes/interval.py

@@ -827,6 +827,28 @@ def _is_comparable_dtype(self, dtype: DtypeObj) -> bool:
 
     @cache_readonly
     def left(self) -> Index:
+        """
+        Return intervals' left value.
+
+        Return number index which contains all intervals' left value
+        in Intervalindex's interval.
+
+        Returns
+        -------
+        Int64Index or Float64Index : depend on if the type of left value.
+
+        See Also
+        --------
+        IntervalIndex : The structure of IntervalIndex.
+
+        Examples
+        --------
+        >>> pd.interval_range(start=0, end=5)
+        IntervalIndex([(0, 1], (1, 2], (2, 3], (3, 4], (4, 5]],
+                        dtype='interval[int64, right]')
+        >>> pd.interval_range(start=0, end=5).left
+        Index([0, 1, 2, 3, 4], dtype='int64')
+        """
         return Index(self._data.left, copy=False)
 
     @cache_readonly
@@ -835,10 +857,54 @@ def right(self) -> Index:
 
     @cache_readonly
     def mid(self) -> Index:
+        """
+        Return the intervals' mean by Float64Index.
+
+        Return Float64Index which contains all intervals' left and right value mean.
+
+        Returns
+        -------
+        Float64Index
+
+        See Also
+        --------
+        IntervalIndex : The structure of IntervalIndex.
+
+        Examples
+        --------
+        >>> pd.interval_range(start=0, end=10, periods=3)
+        IntervalIndex([(0.0, 3.3333333333333335], (3.3333333333333335,
+                    6.666666666666667], (6.666666666666667, 10.0]],
+                    dtype='interval[float64, right]')
+        >>> pd.interval_range(start=0, end=10, periods=3).mid
+        Index([1.6666666666666667, 5.0, 8.333333333333334], dtype='float64')
+        """
         return Index(self._data.mid, copy=False)
 
     @property
     def length(self) -> Index:
+        """
+        Return interval's length.
+
+        Return number index which contains all intervals' length value
+        in Intervalindex's interval.
+
+        Returns
+        -------
+        Int64Index or Float64Index : depend on if the type of length value
+
+        See Also
+        --------
+        IntervalIndex : The structure of IntervalIndex.
+
+        Examples
+        --------
+        >>> pd.interval_range(start=0, end=5)
+        IntervalIndex([(0, 1], (1, 2], (2, 3], (3, 4], (4, 5]],
+                        dtype='interval[int64, right]')
+        >>> pd.interval_range(start=0, end=5).length
+        Index([1, 1, 1, 1, 1], dtype='int64')
+        """
         return Index(self._data.length, copy=False)
 
     # --------------------------------------------------------------------