Compatibility with pandas 1.1.0rc0

[TomAugspurger]

No description provided.

[mrocklin]

Thanks as always for doing this @TomAugspurger

[TomAugspurger]

This should be good to go.

[TomAugspurger]

We won't want this long-tem, since it's a blanket skip whenever we have NumPy 1.20. I've added it now just to keep the number of failures on this branch manageable.

[TomAugspurger]

We'll need to do some work here, but it isn't especially time sensitive or high-priority. Right now you'll just see a warning for datetime columns that can't be silenced.

In [15]: df = pd.DataFrame({"A": pd.date_range("2000", periods=2)})

In [16]: ddf = dd.from_pandas(df, npartitions=1)

In [17]: df.describe()
/Users/taugspurger/.virtualenvs/dask-dev/bin/ipython:1: FutureWarning: Treating datetime data as categorical rather than numeric in `.describe` is deprecated and will be removed in a future version of pandas. Specify `datetime_is_numeric=True` to silence this warning and adopt the future behavior now.
  #!/Users/taugspurger/Envs/dask-dev/bin/python
Out[17]:
                          A
count                     2
unique                    2
top     2000-01-01 00:00:00
freq                      1
first   2000-01-01 00:00:00
last    2000-01-02 00:00:00

In [18]: ddf.describe()
/Users/taugspurger/sandbox/dask/dask/dataframe/core.py:2230: FutureWarning: Treating datetime data as categorical rather than numeric in `.describe` is deprecated and will be removed in a future version of pandas. Specify `datetime_is_numeric=True` to silence this warning and adopt the future behavior now.
  meta = data._meta_nonempty.describe()
/Users/taugspurger/sandbox/dask/dask/dataframe/core.py:2128: FutureWarning: Treating datetime data as categorical rather than numeric in `.describe` is deprecated and will be removed in a future version of pandas. Specify `datetime_is_numeric=True` to silence this warning and adopt the future behavior now.
  meta = self._meta_nonempty.describe(include=include, exclude=exclude)
Out[18]:
Dask DataFrame Structure:
                    A
npartitions=1
               object
                  ...
Dask Name: describe, 19 tasks

In [19]: _.compute()
Out[19]:
                          A
unique                    2
count                     2
top     2000-01-02 00:00:00
freq                      1
first   2000-01-01 00:00:00
last    2000-01-02 00:00:00

[gforsyth]

Hey @TomAugspurger -- does this supersede #6156 ?

[TomAugspurger]

It does, thanks.

[gforsyth]

There's one test failure in the upstream-dev env on Travis but it's a pyarrow error and seems unrelated to this:
https://travis-ci.org/github/dask/dask/jobs/710430328

Should be good to go @dask/maintenance

[TomAugspurger]

Thanks!