ENH: slicing with decreasing monotonic indexes by shoyer · Pull Request #8680 · pandas-dev/pandas (original) (raw)

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shoyer changed the titleWIP: slicing with decreasing monotonic indexes ENH: slicing with decreasing monotonic indexes

Oct 31, 2014

shoyer added a commit to shoyer/pandas that referenced this pull request

Nov 2, 2014

Fixes pandas-dev#7640, pandas-dev#8625

This is a work in progress, but it's far enough along that I'd love to get some feedback.

TODOs (more called out in the code):

• documentation + docstrings
• finish the index methods:
  • get_loc
  • get_indexer
  • slice_locs
• comparison operations
• fix is_monotonic (pending pandas-dev#8680)
• ensure sorting works
• arithmetic operations (not essential for MVP)
• cythonize the bottlenecks:
  • from_breaks
  • _data
  • Interval?
• MultiIndex
• Categorical/cut
• serialization
• lots more tests

CC @jreback @cpcloud @immerrr

Index.is_monotonic will have a performance degradation (still O(n) time) in cases where the Index is decreasing monotonic. If necessary, we could work around this, but I think we can probably get away with this because the fall- back options are much slower and in many cases (e.g., for slice indexing) the next thing we'll want to know is if it's decreasing monotonic, anyways.

see GH7860

also: NaN and NaT imply not monotonic

jreback added a commit that referenced this pull request

Nov 2, 2014

ENH: slicing with decreasing monotonic indexes

shoyer deleted the reversed-monotonic-slices branch

November 2, 2014 22:46