create output dirs before writing data

src/OSmOSE/data/audio_data.py

@@ -112,6 +112,7 @@ def write(self, folder: Path) -> None:
             Folder in which to write the audio file.
 
         """
+        super().write(path=folder)
         sf.write(folder / f"{self}.wav", self.get_value(), self.sample_rate)
 
     def _get_item_value(self, item: AudioItem) -> np.ndarray:

src/OSmOSE/data/base_data.py

@@ -10,6 +10,7 @@
 
 import numpy as np
 
+from OSmOSE.config import DPDEFAULT
 from OSmOSE.data.base_file import BaseFile
 from OSmOSE.data.base_item import BaseItem
 from OSmOSE.data.event import Event
@@ -67,9 +68,12 @@ def get_value(self) -> np.ndarray:
         """Get the concatenated values from all Items."""
         return np.concatenate([item.get_value() for item in self.items])
 
-    def write(self, path: Path) -> None:  # noqa: ARG002
-        """Abstract method for writing the data."""
-        return
+    def write(self, path: Path) -> None:
+        """Create the directory in which the data will be written.
+
+        The actual data writing is left to the specified classes.
+        """
+        path.mkdir(parents=True, exist_ok=True, mode=DPDEFAULT)
 
     @classmethod
     def from_files(