REF: de-duplicate IntervalIndex._intersection (#41929)

Author: jbrockmendel

pandas/core/indexes/interval.py

@@ -802,56 +802,6 @@ def _format_data(self, name=None) -> str:
  # name argument is unused here; just for compat with base / categorical
  return self._data._format_data() + "," + self._format_space()
 
- # --------------------------------------------------------------------
- # Set Operations
-
- def _intersection(self, other, sort):
- """
- intersection specialized to the case with matching dtypes.
- """
- # For IntervalIndex we also know other.closed == self.closed
- if self.left.is_unique and self.right.is_unique:
- return super()._intersection(other, sort=sort)
- elif other.left.is_unique and other.right.is_unique and self.isna().sum() <= 1:
- # Swap other/self if other is unique and self does not have
- # multiple NaNs
- return super()._intersection(other, sort=sort)
- else:
- # duplicates
- taken = self._intersection_non_unique(other)
-
- if sort is None:
- taken = taken.sort_values()
-
- return taken
-
- def _intersection_non_unique(self, other: IntervalIndex) -> IntervalIndex:
- """
- Used when the IntervalIndex does have some common endpoints,
- on either sides.
- Return the intersection with another IntervalIndex.
-
- Parameters
- ----------
- other : IntervalIndex
-
- Returns
- -------
- IntervalIndex
- """
- mask = np.zeros(len(self), dtype=bool)
-
- if self.hasnans and other.hasnans:
- first_nan_loc = np.arange(len(self))[self.isna()][0]
- mask[first_nan_loc] = True
-
- other_tups = set(zip(other.left, other.right))
- for i, tup in enumerate(zip(self.left, self.right)):
- if tup in other_tups:
- mask[i] = True
-
- return self[mask]
-
  # --------------------------------------------------------------------
 
  @property