issue_comments

@patrick-naylor, feel free to try out a better default example if you want.

well, that's just it: there's no way to discriminate between docstrings and multi-line triple-quoted strings without parsing the python code (which is definitely out of scope), so blackdoc doesn't even attempt to. Instead, any line that begins with >>> will be assumed to be doctest lines. So with that, the numbers mean: line 201, character 27.

When created that file we decided to skip the generate_* file, but because the file was renamed that rule does not work anymore. Could you update the pre-commit configuration?

@keewis What does the numbers mean in Cannot parse: 201:27? Because I can't find any functions with docstrings in this file, it's just a bunch of multiline strings that are defined to variables and in my mind shouldn't trigger blackdoc.

do you understand this blackdoc error?

so the reason is the position of the triple quotes: with python def f(): """ >>> 1 + 2""" pass the extracted line will become: 1 + 2""", which when handed to black results in that error.

Technically, that's a bug (the triple quotes mark the end of the docstring), but one that is a bit tricky to fix: blackdoc is implemented using a line parser, which does not work too well if the transition happen somewhere within the line.

My guess is that it would have to start counting quotes which I've tried to avoid up until now since there's a lot of details to get right (see also keewis/blackdoc#145)

Edit: for now, I guess it would be fine to add something like The closing quotes are not on their own line. to the error message

@dcherian cumsum for resample fails for some reason do you have any ideas?

```python import numpy as np import pandas as pd import xarray as xr da = xr.DataArray( np.array([1, 2, 3, 1, 2, np.nan]), dims="time", coords=dict( time=("time", pd.date_range("01-01-2001", freq="M", periods=6)), labels=("time", np.array(["a", "b", "c", "c", "b", "a"])), ), ) ds = xr.Dataset(dict(da=da)) a = ds.resample(time="3M") a.cumsum()

Traceback (most recent call last):

File "C:\Users\J.W\anaconda3\envs\xarray-tests\lib\site-packages\spyder_kernels\py3compat.py", line 356, in compat_exec exec(code, globals, locals)

File "c:\users\j.w\documents\github\xarray\xarray\util\untitled2.py", line 20, in <module> a.cumsum()

File "C:\Users\J.W\Documents\GitHub\xarray\xarray\core_aggregations.py", line 4921, in cumsum return self.reduce(

File "C:\Users\J.W\Documents\GitHub\xarray\xarray\core\resample.py", line 395, in reduce return super().reduce(

File "C:\Users\J.W\Documents\GitHub\xarray\xarray\core\groupby.py", line 1357, in reduce return self.map(reduce_dataset)

File "C:\Users\J.W\Documents\GitHub\xarray\xarray\core\resample.py", line 342, in map return combined.rename({self._resample_dim: self._dim})

File "C:\Users\J.W\Documents\GitHub\xarray\xarray\core\dataset.py", line 3646, in rename return self._rename(name_dict=name_dict, **names)

File "C:\Users\J.W\Documents\GitHub\xarray\xarray\core\dataset.py", line 3587, in _rename raise ValueError(

ValueError: cannot rename 'resample_dim' because it is not a variable or dimension in this dataset ```

@keewis do you understand this blackdoc error?

``` trim trailing whitespace.................................................Passed fix end of files.........................................................Passed check yaml...............................................................Passed debug statements (python)................................................Passed mixed line ending........................................................Passed autoflake................................................................Passed isort....................................................................Passed pyupgrade................................................................Passed black....................................................................Passed black-jupyter............................................................Passed blackdoc.................................................................Failed - hook id: blackdoc - exit code: 123

error: cannot format /code/xarray/util/generate_aggregations.py: Cannot parse: 201:27: EOF in multi-line string Oh no! 💥 💔 💥 215 files left unchanged, 1 file fails to reformat. ```

o you think it would be better to finish this PR as the creation of _aggregations.py to give the cum methods better documentation? Then start a new one to fix https://github.com/pydata/xarray/issues/6528?

Sure that would be a good intermediate step. Let us know if you need help.

Thanks for taking this on @patrick-naylor ! This is a decent-sized project!

Using apply_ufunc and np.cumsum/cumprod has some issues as it only finds the cumulative across one axis which makes iterating through each dimension necessary.

np.cumsum only supports an integer axis so this is OK?

flox doesn't support cumsum at the moment (https://github.com/xarray-contrib/flox/issues/91) so we can delete that bit and just have one code path.

I don't think you have flox installed, if it's not installed the code will take the old path. Do conda install flox and I think you'll get the NotImplementedError. Then you maybe have to change the default settings in cumsum so flox is not used.

Is there a particular reason why there is no cumprod for GroupBy objects?

Nope. Just wasn't added in :)

Thanks @patrick-naylor !

Instead of using Dataset.reduce I think we want something like python def cumsum(..., dim): return xr.apply_ufunc( np.cumsum if skipna else np.nancumsum, obj, input_core_dims=[dim], output_core_dims=[dim], kwargs={"axis": -1}, ) # now transpose dimensions back to input order

to fix #6528.

At the moment, this should also work on GroupBy objects quite nicely.

Right now, I think cumsum and cumprod is enough. numpy-groupies has a few more examples that I suppose we could support in the future.

Very nice, this is something that's been on the TODO list! :)

I believe we wanted to rename generate_reductions.py to generate_aggregations.py so cumsum et al could be included and generated there as well. Is there a lot of work for you if try to merge these into that one?