REGR: Series.nlargest with masked arrays #42838
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jbrockmendel
commented
Jul 31, 2021
jbrockmendel
commented
- closes BUG: nlargest raises TypeError "No matching signature found" on Float64Dtype Series, versions >1.3.0 #42816
- tests added / passed
- Ensure all linting tests pass, see here for how to run them
- whatsnew entry
jbrockmendel
added
NA - MaskedArrays
| @@ -1255,6 +1259,18 @@ def compute(self, method: str) -> Series: | |||
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| dropped = self.obj.dropna() | |||
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| if is_extension_array_dtype(dropped.dtype): | |||
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why is this prefereable to hanlding on L1281 with the other dtypes?
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bc ensure_data does the wrong thing with MaskedArrays, np.asarray(obj) defaults to object dtype.
we could kludge _ensure_data to work in cases where we dont have any pd.NAs, but doing it here lets us handle cases with NAs too.
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bc ensure_data does the wrong thing with MaskedArrays, np.asarray(obj) defaults to object dtype.
this is very unfortunate. I don't really like this approach here. i suppose its ok for a backport though this is na experimental type and so i don't consider this regression to be a big deal.
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the more i work on it, the more i want to nuke NA from space
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ok what is involved with changing this to a non-recursive formulation though? e.g. ensure_data should be able to handle NA (if not we will have other issues)
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Three options:
- have ensure_data special-case MaskedArray cases with no NAs, in which case they can just use the ndarray. This fixes the regression (cases with NAs didnt use to work IIUC). kluuuuudge
- make algos.kth_smallest support object dtype (and not choke on pd.NA)
- make the EA implement its own nlargest
I decided the approach here was less kludgy than those in part bc this function uses obj.dropna(), so the MaskedArray case actually is much simpler to implement than an arbitrary EA
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bc its special-casing for MaskedArray and special casing for not values.isna().any()
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worse than that, it isnt not values.isna().any() but not values._mask.any()
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not super thrilled with this, but does fix. |
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@meeseeksdev backport 1.3.x |
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Something went wrong ... Please have a look at my logs. |
| @@ -23,6 +23,7 @@ Fixed regressions | |||
| - Fixed regression where :meth:`pandas.read_csv` raised a ``ValueError`` when parameters ``names`` and ``prefix`` were both set to None (:issue:`42387`) | |||
| - Fixed regression in comparisons between :class:`Timestamp` object and ``datetime64`` objects outside the implementation bounds for nanosecond ``datetime64`` (:issue:`42794`) | |||
| - Fixed regression in :meth:`.Styler.highlight_min` and :meth:`.Styler.highlight_max` where ``pandas.NA`` was not successfully ignored (:issue:`42650`) | |||
| - Regression in :meth:`Series.nlargest` and :meth:`Series.nsmallest` with nullable integer or float dtype (:issue:`41816`) | |||
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will need to change to #42816. will do that after backport is merged.
… arrays) (#42975) * Backport PR #42838: REGR: Series.nlargest with masked arrays * fix final import Co-authored-by: jbrockmendel <[email protected]>
