Merge branch 'main' into backend-indexing

* main: (54 commits)
  Adding `open_datatree` backend-specific keyword arguments (#9199)
  [pre-commit.ci] pre-commit autoupdate (#9202)
  Restore ability to specify _FillValue as Python native integers (#9258)
  add backend intro and how-to diagram (#9175)
  Fix copybutton for multi line examples in double digit ipython cells (#9264)
  Update signature for _arrayfunction.__array__ (#9237)
  Add encode_cf_datetime benchmark (#9262)
  groupby, resample: Deprecate some positional args (#9236)
  Delete ``base`` and ``loffset`` parameters to resample (#9233)
  Update dropna docstring (#9257)
  Grouper, Resampler as public api (#8840)
  Fix mypy on main (#9252)
  fix fallback isdtype method (#9250)
  Enable pandas type checking (#9213)
  Per-variable specification of boolean parameters in open_dataset (#9218)
  test push
  Added a space to the documentation (#9247)
  Fix typing for test_plot.py (#9234)
  Allow mypy to run in vscode (#9239)
  Revert "Test main push"
  ...

.github/release.yml

@@ -0,0 +1,5 @@
+changelog:
+  exclude:
+    authors:
+      - dependabot
+      - pre-commit-ci

.pre-commit-config.yaml

@@ -13,7 +13,7 @@ repos:
       - id: mixed-line-ending
   - repo: https://github.com/astral-sh/ruff-pre-commit
     # Ruff version.
-    rev: 'v0.4.7'
+    rev: 'v0.5.0'
     hooks:
       - id: ruff
         args: ["--fix", "--show-fixes"]
@@ -30,7 +30,7 @@ repos:
         additional_dependencies: ["black==24.4.2"]
       - id: blackdoc-autoupdate-black
   - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v1.10.0
+    rev: v1.10.1
     hooks:
       - id: mypy
         # Copied from setup.cfg

asv_bench/benchmarks/coding.py

@@ -0,0 +1,18 @@
+import numpy as np
+
+import xarray as xr
+
+from . import parameterized
+
+
+@parameterized(["calendar"], [("standard", "noleap")])
+class EncodeCFDatetime:
+    def setup(self, calendar):
+        self.units = "days since 2000-01-01"
+        self.dtype = np.dtype("int64")
+        self.times = xr.date_range(
+            "2000", freq="D", periods=10000, calendar=calendar
+        ).values
+
+    def time_encode_cf_datetime(self, calendar):
+        xr.coding.times.encode_cf_datetime(self.times, self.units, calendar, self.dtype)

asv_bench/benchmarks/dataset_io.py

@@ -7,6 +7,8 @@
 import pandas as pd
 
 import xarray as xr
+from xarray.backends.api import open_datatree
+from xarray.core.datatree import DataTree
 
 from . import _skip_slow, parameterized, randint, randn, requires_dask
 
@@ -16,7 +18,6 @@
 except ImportError:
     pass
 
-
 os.environ["HDF5_USE_FILE_LOCKING"] = "FALSE"
 
 _ENGINES = tuple(xr.backends.list_engines().keys() - {"store"})
@@ -469,6 +470,116 @@ def create_delayed_write():
     return ds.to_netcdf("file.nc", engine="netcdf4", compute=False)
 
 
+class IONestedDataTree:
+    """
+    A few examples that benchmark reading/writing a heavily nested netCDF datatree with
+    xarray
+    """
+
+    timeout = 300.0
+    repeat = 1
+    number = 5
+
+    def make_datatree(self, nchildren=10):
+        # multiple Dataset
+        self.ds = xr.Dataset()
+        self.nt = 1000
+        self.nx = 90
+        self.ny = 45
+        self.nchildren = nchildren
+
+        self.block_chunks = {
+            "time": self.nt / 4,
+            "lon": self.nx / 3,
+            "lat": self.ny / 3,
+        }
+
+        self.time_chunks = {"time": int(self.nt / 36)}
+
+        times = pd.date_range("1970-01-01", periods=self.nt, freq="D")
+        lons = xr.DataArray(
+            np.linspace(0, 360, self.nx),
+            dims=("lon",),
+            attrs={"units": "degrees east", "long_name": "longitude"},
+        )
+        lats = xr.DataArray(
+            np.linspace(-90, 90, self.ny),
+            dims=("lat",),
+            attrs={"units": "degrees north", "long_name": "latitude"},
+        )
+        self.ds["foo"] = xr.DataArray(
+            randn((self.nt, self.nx, self.ny), frac_nan=0.2),
+            coords={"lon": lons, "lat": lats, "time": times},
+            dims=("time", "lon", "lat"),
+            name="foo",
+            attrs={"units": "foo units", "description": "a description"},
+        )
+        self.ds["bar"] = xr.DataArray(
+            randn((self.nt, self.nx, self.ny), frac_nan=0.2),
+            coords={"lon": lons, "lat": lats, "time": times},
+            dims=("time", "lon", "lat"),
+            name="bar",
+            attrs={"units": "bar units", "description": "a description"},
+        )
+        self.ds["baz"] = xr.DataArray(
+            randn((self.nx, self.ny), frac_nan=0.2).astype(np.float32),
+            coords={"lon": lons, "lat": lats},
+            dims=("lon", "lat"),
+            name="baz",
+            attrs={"units": "baz units", "description": "a description"},
+        )
+
+        self.ds.attrs = {"history": "created for xarray benchmarking"}
+
+        self.oinds = {
+            "time": randint(0, self.nt, 120),
+            "lon": randint(0, self.nx, 20),
+            "lat": randint(0, self.ny, 10),
+        }
+        self.vinds = {
+            "time": xr.DataArray(randint(0, self.nt, 120), dims="x"),
+            "lon": xr.DataArray(randint(0, self.nx, 120), dims="x"),
+            "lat": slice(3, 20),
+        }
+        root = {f"group_{group}": self.ds for group in range(self.nchildren)}
+        nested_tree1 = {
+            f"group_{group}/subgroup_1": xr.Dataset() for group in range(self.nchildren)
+        }
+        nested_tree2 = {
+            f"group_{group}/subgroup_2": xr.DataArray(np.arange(1, 10)).to_dataset(
+                name="a"
+            )
+            for group in range(self.nchildren)
+        }
+        nested_tree3 = {
+            f"group_{group}/subgroup_2/sub-subgroup_1": self.ds
+            for group in range(self.nchildren)
+        }
+        dtree = root | nested_tree1 | nested_tree2 | nested_tree3
+        self.dtree = DataTree.from_dict(dtree)
+
+
+class IOReadDataTreeNetCDF4(IONestedDataTree):
+    def setup(self):
+        # TODO: Lazily skipped in CI as it is very demanding and slow.
+        # Improve times and remove errors.
+        _skip_slow()
+
+        requires_dask()
+
+        self.make_datatree()
+        self.format = "NETCDF4"
+        self.filepath = "datatree.nc4.nc"
+        dtree = self.dtree
+        dtree.to_netcdf(filepath=self.filepath)
+
+    def time_load_datatree_netcdf4(self):
+        open_datatree(self.filepath, engine="netcdf4").load()
+
+    def time_open_datatree_netcdf4(self):
+        open_datatree(self.filepath, engine="netcdf4")
+
+
 class IOWriteNetCDFDask:
     timeout = 60
     repeat = 1

ci/install-upstream-wheels.sh

@@ -13,7 +13,7 @@ $conda remove -y numba numbagg sparse
 # temporarily remove numexpr
 $conda remove -y numexpr
 # temporarily remove backends
-$conda remove -y cf_units hdf5 h5py netcdf4 pydap
+$conda remove -y pydap
 # forcibly remove packages to avoid artifacts
 $conda remove -y --force \
     numpy \
@@ -37,8 +37,7 @@ python -m pip install \
     numpy \
     scipy \
     matplotlib \
-    pandas \
-    h5py
+    pandas
 # for some reason pandas depends on pyarrow already.
 # Remove once a `pyarrow` version compiled with `numpy>=2.0` is on `conda-forge`
 python -m pip install \

ci/requirements/all-but-dask.yml

@@ -27,7 +27,7 @@ dependencies:
   - pandas
   - pint>=0.22
   - pip
-  - pydap
+  # - pydap
   - pytest
   - pytest-cov
   - pytest-env

ci/requirements/doc.yml

@@ -21,7 +21,7 @@ dependencies:
   - nbsphinx
   - netcdf4>=1.5
   - numba
-  - numpy>=1.21
+  - numpy>=2
   - packaging>=21.3
   - pandas>=1.4,!=2.1.0
   - pooch
@@ -42,5 +42,6 @@ dependencies:
   - sphinxext-rediraffe
   - zarr>=2.10
   - pip:
+      - sphinxcontrib-mermaid
       # relative to this file. Needs to be editable to be accepted.
       - -e ../..

ci/requirements/environment-windows.yml

@@ -29,7 +29,7 @@ dependencies:
   # - pint>=0.22
   - pip
   - pre-commit
-  - pydap
+  # - pydap
   - pytest
   - pytest-cov
   - pytest-env

ci/requirements/environment.yml

@@ -35,7 +35,7 @@ dependencies:
   - pooch
   - pre-commit
   - pyarrow # pandas raises a deprecation warning without this, breaking doctests
-  - pydap
+  # - pydap
   - pytest
   - pytest-cov
   - pytest-env

doc/api-hidden.rst

@@ -693,3 +693,7 @@
 
    coding.times.CFTimedeltaCoder
    coding.times.CFDatetimeCoder
+
+   core.groupers.Grouper
+   core.groupers.Resampler
+   core.groupers.EncodedGroups

doc/api.rst

@@ -111,6 +111,7 @@ Dataset contents
    Dataset.drop_duplicates
    Dataset.drop_dims
    Dataset.drop_encoding
+   Dataset.drop_attrs
    Dataset.set_coords
    Dataset.reset_coords
    Dataset.convert_calendar
@@ -306,6 +307,7 @@ DataArray contents
    DataArray.drop_indexes
    DataArray.drop_duplicates
    DataArray.drop_encoding
+   DataArray.drop_attrs
    DataArray.reset_coords
    DataArray.copy
    DataArray.convert_calendar
@@ -801,6 +803,18 @@ DataArray
    DataArrayGroupBy.dims
    DataArrayGroupBy.groups
 
+Grouper Objects
+---------------
+
+.. currentmodule:: xarray.core
+
+.. autosummary::
+   :toctree: generated/
+
+   groupers.BinGrouper
+   groupers.UniqueGrouper
+   groupers.TimeResampler
+
 
 Rolling objects
 ===============
@@ -1026,17 +1040,20 @@ DataArray
 Accessors
 =========
 
-.. currentmodule:: xarray
+.. currentmodule:: xarray.core
 
 .. autosummary::
    :toctree: generated/
 
-   core.accessor_dt.DatetimeAccessor
-   core.accessor_dt.TimedeltaAccessor
-   core.accessor_str.StringAccessor
+   accessor_dt.DatetimeAccessor
+   accessor_dt.TimedeltaAccessor
+   accessor_str.StringAccessor
+
 
 Custom Indexes
 ==============
+.. currentmodule:: xarray
+
 .. autosummary::
    :toctree: generated/
 

doc/conf.py

@@ -59,6 +59,7 @@
     )
 
 nbsphinx_allow_errors = False
+nbsphinx_requirejs_path = ""
 
 # -- General configuration ------------------------------------------------
 
@@ -68,7 +69,9 @@
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
+
 extensions = [
+    "sphinxcontrib.mermaid",
     "sphinx.ext.autodoc",
     "sphinx.ext.autosummary",
     "sphinx.ext.intersphinx",
@@ -94,7 +97,7 @@
 }
 
 # sphinx-copybutton configurations
-copybutton_prompt_text = r">>> |\.\.\. |\$ |In \[\d*\]: | {2,5}\.\.\.: | {5,8}: "
+copybutton_prompt_text = r">>> |\.\.\. |\$ |In \[\d*\]: | {2,5}\.{3,}: | {5,8}: "
 copybutton_prompt_is_regexp = True
 
 # nbsphinx configurations
@@ -155,6 +158,8 @@
     "Variable": "~xarray.Variable",
     "DatasetGroupBy": "~xarray.core.groupby.DatasetGroupBy",
     "DataArrayGroupBy": "~xarray.core.groupby.DataArrayGroupBy",
+    "Grouper": "~xarray.core.groupers.Grouper",
+    "Resampler": "~xarray.core.groupers.Resampler",
     # objects without namespace: numpy
     "ndarray": "~numpy.ndarray",
     "MaskedArray": "~numpy.ma.MaskedArray",
@@ -166,6 +171,7 @@
     "CategoricalIndex": "~pandas.CategoricalIndex",
     "TimedeltaIndex": "~pandas.TimedeltaIndex",
     "DatetimeIndex": "~pandas.DatetimeIndex",
+    "IntervalIndex": "~pandas.IntervalIndex",
     "Series": "~pandas.Series",
     "DataFrame": "~pandas.DataFrame",
     "Categorical": "~pandas.Categorical",
@@ -175,6 +181,8 @@
     "pd.NaT": "~pandas.NaT",
 }
 
+# mermaid config
+mermaid_version = "10.9.1"
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ["_templates", sphinx_autosummary_accessors.templates_path]

doc/getting-started-guide/faq.rst

@@ -352,9 +352,9 @@ Some packages may have additional functionality beyond what is shown here. You c
 How does xarray handle missing values?
 --------------------------------------
 
-**xarray can handle missing values using ``np.NaN``**
+**xarray can handle missing values using ``np.nan``**
 
-- ``np.NaN`` is  used to represent missing values in labeled arrays and datasets. It is a commonly used standard for representing missing or undefined numerical data in scientific computing. ``np.NaN`` is a constant value in NumPy that represents "Not a Number" or missing values.
+- ``np.nan`` is  used to represent missing values in labeled arrays and datasets. It is a commonly used standard for representing missing or undefined numerical data in scientific computing. ``np.nan`` is a constant value in NumPy that represents "Not a Number" or missing values.
 
 - Most of xarray's computation methods are designed to automatically handle missing values appropriately.