Create intermediate directories when writing to file with .to_netcdf methods.

docs/release-notes.md

@@ -1,8 +1,10 @@
 # Release notes
 
 ## 0.2.5
-- Fix numpy 2.4 and obspy 1.4.2 incompatibilities (@atrabatto).
 - Add SampleCoordinate for more SEED-like coordinates (@atrabattoni).
+- Add `create_dirs` to `.to_netcdf` methods to create intermediate directories (@aurelienfalco).
+- Fix numpy 2.4 and obspy 1.4.2 incompatibilities (@atrabatto).
+
 
 ## 0.2.4
 - Add StreamWriter to write long time series to miniSEED (@marbail).

tests/test_dataarray.py

@@ -458,6 +458,16 @@ def test_io_attrs(self):
             assert result.attrs == attrs
             assert result.equals(da)
 
+    def test_io_create_dirs(self):
+        da = xd.DataArray(np.arange(3))
+        with TemporaryDirectory() as dirpath:
+            path = os.path.join(dirpath, "subdir", "tmp.nc")
+            with pytest.raises(FileNotFoundError, match="No such file or directory"):
+                da.to_netcdf(path)
+            da.to_netcdf(path, create_dirs=True)
+            result = xd.DataArray.from_netcdf(path)
+            assert result.equals(da)
+
     def test_ufunc(self):
         da = wavelet_wavefronts()
         result = np.add(da, 1)

tests/test_datacollection.py

@@ -68,6 +68,23 @@ def test_io(self):
             result = xd.open_datacollection(path)
             assert result.equals(dc)
 
+    def test_io_create_dirs(self):
+        da = wavelet_wavefronts()
+        dc = xd.DataCollection(
+            {
+                "das1": da,
+                "das2": da,
+            },
+            "instrument",
+        )
+        with TemporaryDirectory() as dirpath:
+            path = os.path.join(dirpath, "subdir", "tmp.nc")
+            with pytest.raises(FileNotFoundError, match="No such file or directory"):
+                dc.to_netcdf(path)
+            dc.to_netcdf(path, create_dirs=True)
+            result = xd.DataCollection.from_netcdf(path)
+            assert result.equals(dc)
+
     def test_depth_counter(self):
         da = wavelet_wavefronts()
         da.name = "da"

xdas/core/dataarray.py

@@ -1,4 +1,5 @@
 import copy
+import os
 import warnings
 from functools import partial
 
@@ -825,7 +826,15 @@ def from_stream(cls, st, dims=("channel", "time")):
         }
         return cls(data, {dims[0]: channel, dims[1]: time})
 
-    def to_netcdf(self, fname, mode="w", group=None, virtual=None, encoding=None):
+    def to_netcdf(
+        self,
+        fname,
+        mode="w",
+        group=None,
+        virtual=None,
+        encoding=None,
+        create_dirs=False,
+    ):
         """
         Write DataArray contents to a netCDF file.
 
@@ -849,6 +858,8 @@ def to_netcdf(self, fname, mode="w", group=None, virtual=None, encoding=None):
             the `h5netcdf` engine to write the data. If you want to use a specific plugin
             for compression, you can use the `hdf5plugin` package. For example, to use the
             ZFP compression, you can use the `hdf5plugin.Zfp` class.
+        create_dirs : bool, optional
+            Whether to create parent directories if they do not exist. Default is False.
 
         Examples
         --------
@@ -883,6 +894,12 @@ def to_netcdf(self, fname, mode="w", group=None, virtual=None, encoding=None):
         for coord in self.coords.values():
             dataset, variable_attrs = coord.to_dataset(dataset, variable_attrs)
 
+        # create parent directories if needed
+        if create_dirs:
+            dirname = os.path.dirname(fname)
+            if dirname:
+                os.makedirs(dirname, exist_ok=True)
+
         # write data
         with h5netcdf.File(fname, mode=mode) as file:
             # group

xdas/core/datacollection.py

@@ -231,14 +231,26 @@ def fields(self):
         )
         return uniquifiy(out)
 
-    def to_netcdf(self, fname, mode="w", group=None, virtual=None, encoding=None):
+    def to_netcdf(
+        self,
+        fname,
+        mode="w",
+        group=None,
+        virtual=None,
+        encoding=None,
+        create_dirs=False,
+    ):
         if mode == "w" and group is None and os.path.exists(fname):
             os.remove(fname)
         for key in self:
             name = self.name if self.name is not None else "collection"
             location = "/".join([name, str(key)])
             if group is not None:
                 location = "/".join([group, location])
+            if create_dirs:
+                dirname = os.path.dirname(fname)
+                if dirname:
+                    os.makedirs(dirname, exist_ok=True)
             self[key].to_netcdf(
                 fname,
                 mode="a",
@@ -441,9 +453,22 @@ def to_mapping(self):
     def from_mapping(cls, data):
         return cls(data.values(), data.name)
 
-    def to_netcdf(self, fname, mode="w", group=None, virtual=None, encoding=None):
+    def to_netcdf(
+        self,
+        fname,
+        mode="w",
+        group=None,
+        virtual=None,
+        encoding=None,
+        create_dirs=False,
+    ):
         self.to_mapping().to_netcdf(
-            fname, mode=mode, group=group, virtual=virtual, encoding=encoding
+            fname,
+            mode=mode,
+            group=group,
+            virtual=virtual,
+            encoding=encoding,
+            create_dirs=create_dirs,
         )
 
     @classmethod