diff --git a/pandas/core/missing.py b/pandas/core/missing.py index b3e152e36a304..9fef78d9f8c3d 100644 --- a/pandas/core/missing.py +++ b/pandas/core/missing.py @@ -471,20 +471,20 @@ def _interpolate_1d( if valid.all(): return - # These are sets of index pointers to invalid values... i.e. {0, 1, etc... - all_nans = set(np.flatnonzero(invalid)) + # These index pointers to invalid values... i.e. {0, 1, etc... + all_nans = np.flatnonzero(invalid) first_valid_index = find_valid_index(how="first", is_valid=valid) if first_valid_index is None: # no nan found in start first_valid_index = 0 - start_nans = set(range(first_valid_index)) + start_nans = np.arange(first_valid_index) last_valid_index = find_valid_index(how="last", is_valid=valid) if last_valid_index is None: # no nan found in end last_valid_index = len(yvalues) - end_nans = set(range(1 + last_valid_index, len(valid))) + end_nans = np.arange(1 + last_valid_index, len(valid)) - # Like the sets above, preserve_nans contains indices of invalid values, + # preserve_nans contains indices of invalid values, # but in this case, it is the final set of indices that need to be # preserved as NaN after the interpolation. @@ -493,27 +493,25 @@ def _interpolate_1d( # are more than 'limit' away from the prior non-NaN. # set preserve_nans based on direction using _interp_limit - preserve_nans: list | set if limit_direction == "forward": - preserve_nans = start_nans | set(_interp_limit(invalid, limit, 0)) + preserve_nans = np.union1d(start_nans, _interp_limit(invalid, limit, 0)) elif limit_direction == "backward": - preserve_nans = end_nans | set(_interp_limit(invalid, 0, limit)) + preserve_nans = np.union1d(end_nans, _interp_limit(invalid, 0, limit)) else: # both directions... just use _interp_limit - preserve_nans = set(_interp_limit(invalid, limit, limit)) + preserve_nans = np.unique(_interp_limit(invalid, limit, limit)) # if limit_area is set, add either mid or outside indices # to preserve_nans GH #16284 if limit_area == "inside": # preserve NaNs on the outside - preserve_nans |= start_nans | end_nans + preserve_nans = np.union1d(preserve_nans, start_nans) + preserve_nans = np.union1d(preserve_nans, end_nans) elif limit_area == "outside": # preserve NaNs on the inside - mid_nans = all_nans - start_nans - end_nans - preserve_nans |= mid_nans - - # sort preserve_nans and convert to list - preserve_nans = sorted(preserve_nans) + mid_nans = np.setdiff1d(all_nans, start_nans, assume_unique=True) + mid_nans = np.setdiff1d(mid_nans, end_nans, assume_unique=True) + preserve_nans = np.union1d(preserve_nans, mid_nans) is_datetimelike = yvalues.dtype.kind in "mM" @@ -1027,7 +1025,7 @@ def clean_reindex_fill_method(method) -> ReindexMethod | None: def _interp_limit( invalid: npt.NDArray[np.bool_], fw_limit: int | None, bw_limit: int | None -): +) -> np.ndarray: """ Get indexers of values that won't be filled because they exceed the limits. @@ -1059,20 +1057,23 @@ def _interp_limit(invalid, fw_limit, bw_limit): # 1. operate on the reversed array # 2. subtract the returned indices from N - 1 N = len(invalid) - f_idx = set() - b_idx = set() + f_idx = np.array([], dtype=np.int64) + b_idx = np.array([], dtype=np.int64) + assume_unique = True def inner(invalid, limit: int): limit = min(limit, N) - windowed = _rolling_window(invalid, limit + 1).all(1) - idx = set(np.where(windowed)[0] + limit) | set( - np.where((~invalid[: limit + 1]).cumsum() == 0)[0] + windowed = np.lib.stride_tricks.sliding_window_view(invalid, limit + 1).all(1) + idx = np.union1d( + np.where(windowed)[0] + limit, + np.where((~invalid[: limit + 1]).cumsum() == 0)[0], ) return idx if fw_limit is not None: if fw_limit == 0: - f_idx = set(np.where(invalid)[0]) + f_idx = np.where(invalid)[0] + assume_unique = False else: f_idx = inner(invalid, fw_limit) @@ -1082,26 +1083,8 @@ def inner(invalid, limit: int): # just use forwards return f_idx else: - b_idx_inv = list(inner(invalid[::-1], bw_limit)) - b_idx = set(N - 1 - np.asarray(b_idx_inv)) + b_idx = N - 1 - inner(invalid[::-1], bw_limit) if fw_limit == 0: return b_idx - return f_idx & b_idx - - -def _rolling_window(a: npt.NDArray[np.bool_], window: int) -> npt.NDArray[np.bool_]: - """ - [True, True, False, True, False], 2 -> - - [ - [True, True], - [True, False], - [False, True], - [True, False], - ] - """ - # https://stackoverflow.com/a/6811241 - shape = a.shape[:-1] + (a.shape[-1] - window + 1, window) - strides = a.strides + (a.strides[-1],) - return np.lib.stride_tricks.as_strided(a, shape=shape, strides=strides) + return np.intersect1d(f_idx, b_idx, assume_unique=assume_unique)