issue_comments

@shoyer can you take a look at the approach here? I'd like to finish this off soon.

______ [doctest] xarray.core._reductions.DatasetResampleReductions.count _______ 3063 >>> ds 3064 <xarray.Dataset> 3065 Dimensions: (time: 6) 3066 Coordinates: 3067 * time (time) datetime64[ns] 2001-01-31 2001-02-28 ... 2001-06-30 3068 labels (time) <U1 'a' 'b' 'c' 'c' 'b' 'a' 3069 Data variables: 3070 da (time) float64 1.0 2.0 3.0 1.0 2.0 nan 3071 3072 >>> ds.resample(time="3M").count() Differences (unified diff with -expected +actual): @@ -4,3 +4,3 @@ * time (time) datetime64[ns] 2001-01-31 2001-04-30 2001-07-31 Data variables: - da (time) int32 1 3 1 + da (time) int64 1 3 1 I wonder why I don't get the same result?

My request was for #5734 but after merging the latest version of this branch, it passes! Thanks for checking.

@dcherian does this mean the typing issue you mentioned is fixed? Or was that a different PR?

Keyword-only and some had the 3rd position arg as keep_attrs and in other cases it was axis.

Thanks @Illviljan

a slightly breaking change now since some of these reduce functions had quite different arguments.

Can you describe these changes please? Is it the switch to keyword-only?

@dcherian I'm getting errors when I attempt to generate the doc examples:

I get similar issues with the other commands as well using Windows 10. I managed to copy paste the output of generate_reductions so I got it running that way instead.

It passes all tests besides doctests now which a proper rerun should fix. This became a slightly breaking change now since some of these reduce functions had quite different arguments.

yeah, I saw that one, The groupby reduces doesn't have consistent args, finally mypy is being helpful. :)

still failing :( xarray/core/groupby.py:881: error: Definition of "reduce" in base class "DataArrayGroupByBase" is incompatible with definition in base class "DataArrayGroupByReductions" [misc] xarray/core/groupby.py:1004: error: Definition of "reduce" in base class "DatasetGroupByBase" is incompatible with definition in base class "DatasetGroupByReductions" [misc] xarray/core/dataset.py:4999: error: Argument 3 of "reduce" is incompatible with supertype "DatasetReductions"; supertype defines the argument type as "Union[int, Sequence[int], None]" [override] xarray/core/dataset.py:4999: note: This violates the Liskov substitution principle xarray/core/dataset.py:4999: note: See https://mypy.readthedocs.io/en/stable/common_issues.html#incompatible-overrides xarray/core/dataset.py:4999: error: Argument 4 of "reduce" is incompatible with supertype "DatasetReductions"; supertype defines the argument type as "Optional[bool]" [override] xarray/core/resample.py:160: error: Definition of "reduce" in base class "DataArrayGroupByBase" is incompatible with definition in base class "DataArrayResampleReductions" [misc] Found 5 errors in 3 files (checked 2 source files)

I'vebeen using Usage: python xarray/util/generate_reductions.py > xarray/core/_reductions.py pytest --doctest-modules xarray/core/_reductions.py --accept || true pytest --doctest-modules xarray/core/_reductions.py to generate the file

@dcherian could you run the generate_reductions.py now? I get some weird formatting issues on the docstrings when I copy paste from the console. :/ I think this fixes the typing issues. At least it was passing locally.

These mypy errors are quite tricky. Any ideas how to solve them? Here's a stripped down example:

```python class DatasetReduce2(Protocol): def reduce(self, func: Callable): ...

class DatasetReductions2: def sum(self: DatasetReduce2, dim: Hashable) -> int: return self.reduce(lambda x: x)

class Test(DatasetReductions2): def init(self, a, b): self.a = a self.b = b

a = Test(1, 2) a.sum("z") Invalid self argument "Test" to attribute function "sum" with type "Callable[[DatasetReduce2, Hashable], int] ```

It's posssible to avoid the failures using the previous import way instead of mixing in directly in the dataset/dataarray class, But I think the typing is simply stripped then instead, so that's no good either.

Interesting reading: https://stackoverflow.com/questions/51930339/how-do-i-correctly-add-type-hints-to-mixin-classes

xarray/tests/test_groupby.py:77: error: Invalid self argument "Dataset" to attribute function "sum" with type "Callable[[DatasetReduce, Optional[Hashable], Optional[bool], Optional[int], Optional[bool], KwArg(Any)], T_Dataset]" [misc] xarray/tests/test_groupby.py:77: error: Need type annotation for "expected" [var-annotated] Maybe these are fixed with callback protocols? https://github.com/python/mypy/issues/5485 https://mypy.readthedocs.io/en/latest/protocols.html#callback-protocols

Could use some help with typing...

xarray/tests/test_groupby.py:77: error: Invalid self argument "Dataset" to attribute function "sum" with type "Callable[[DatasetReduce, Optional[Hashable], Optional[bool], Optional[int], Optional[bool], KwArg(Any)], T_Dataset]" [misc] xarray/tests/test_groupby.py:77: error: Need type annotation for "expected" [var-annotated] xarray/tests/test_groupby.py:460: error: Invalid self argument "Dataset" to attribute function "mean" with type "Callable[[DatasetReduce, Optional[Hashable], Optional[bool], Optional[bool], KwArg(Any)], T_Dataset]" [misc] xarray/tests/test_groupby.py:460: error: <nothing> has no attribute "where" [attr-defined] xarray/tests/test_groupby.py:646: error: Invalid self argument "Dataset" to attribute function "mean" with type "Callable[[DatasetReduce, Optional[Hashable], Optional[bool], Optional[bool], KwArg(Any)], T_Dataset]" [misc] xarray/tests/test_groupby.py:646: error: Need type annotation for "expected" [var-annotated] xarray/tests/test_groupby.py:658: error: Invalid self argument "DataArray" to attribute function "mean" with type "Callable[[DataArrayReduce, Optional[Hashable], Optional[bool], Optional[bool], KwArg(Any)], T_DataArray]" [misc] xarray/tests/test_groupby.py:658: error: <nothing> has no attribute "variable" [attr-defined] xarray/tests/test_computation.py:1867: error: Invalid self argument "DataArray" to attribute function "sum" with type "Callable[[DataArrayReduce, Optional[Hashable], Optional[bool], Optional[int], Optional[bool], KwArg(Any)], T_DataArray]" [misc] xarray/tests/test_computation.py:1867: error: Need type annotation for "expected" [var-annotated] xarray/tests/test_computation.py:1867: error: Argument 1 to "sum" of "DataArrayReductions" has incompatible type "List[str]"; expected "Optional[Hashable]" [arg-type] xarray/tests/test_computation.py:1867: note: Following member(s) of "List[str]" have conflicts: xarray/tests/test_computation.py:1867: note: __hash__: expected "Callable[[], int]", got "None" xarray/tests/test_computation.py:1871: error: Invalid self argument "DataArray" to attribute function "sum" with type "Callable[[DataArrayReduce, Optional[Hashable], Optional[bool], Optional[int], Optional[bool], KwArg(Any)], T_DataArray]" [misc] xarray/tests/test_computation.py:1882: error: Invalid self argument "DataArray" to attribute function "sum" with type "Callable[[DataArrayReduce, Optional[Hashable], Optional[bool], Optional[int], Optional[bool], KwArg(Any)], T_DataArray]" [misc] xarray/tests/test_computation.py:1882: error: Argument 1 to "sum" of "DataArrayReductions" has incompatible type "List[str]"; expected "Optional[Hashable]" [arg-type] xarray/tests/test_computation.py:1882: note: Following member(s) of "List[str]" have conflicts: xarray/tests/test_computation.py:1882: note: __hash__: expected "Callable[[], int]", got "None" xarray/tests/test_computation.py:1887: error: Invalid self argument "DataArray" to attribute function "sum" with type "Callable[[DataArrayReduce, Optional[Hashable], Optional[bool], Optional[int], Optional[bool], KwArg(Any)], T_DataArray]" [misc] xarray/tests/test_computation.py:1887: error: Argument 1 to "sum" of "DataArrayReductions" has incompatible type "List[str]"; expected "Optional[Hashable]" [arg-type] xarray/tests/test_computation.py:1887: note: Following member(s) of "List[str]" have conflicts: xarray/tests/test_computation.py:1887: note: __hash__: expected "Callable[[], int]", got "None" xarray/tests/test_computation.py:1892: error: Invalid self argument "DataArray" to attribute function "sum" with type "Callable[[DataArrayReduce, Optional[Hashable], Optional[bool], Optional[int], Optional[bool], KwArg(Any)], T_DataArray]" [misc] xarray/tests/test_computation.py:1892: error: Argument 1 to "sum" of "DataArrayReductions" has incompatible type "List[str]"; expected "Optional[Hashable]" [arg-type] xarray/tests/test_computation.py:1892: note: Following member(s) of "List[str]" have conflicts: xarray/tests/test_computation.py:1892: note: __hash__: expected "Callable[[], int]", got "None"