add methods to load and save preprocessing config

batdetect2/data/preprocessing.py

@@ -1,6 +1,7 @@
 """Module containing functions for preprocessing audio clips."""
 
-from typing import Optional
+from typing import Optional, Union
+from pathlib import Path
 
 import librosa
 import librosa.core.spectrum
@@ -60,6 +61,46 @@ class PreprocessingConfig(BaseModel):
 
     spec_time_period: float = SPEC_TIME_PERIOD
 
+    @classmethod
+    def from_file(
+        cls,
+        path: Union[str, Path],
+    ) -> "PreprocessingConfig":
+        """Load configuration from a file.
+
+        Parameters
+        ----------
+        path
+            Path to the configuration file.
+
+        Returns
+        -------
+        PreprocessingConfig
+            The configuration loaded from the file.
+
+        Raises
+        ------
+        FileNotFoundError
+            If the configuration file does not exist.
+        pydantic.ValidationError
+            If the configuration file is invalid.
+        """
+        path = Path(path)
+
+        if not path.is_file():
+            raise FileNotFoundError(f"Config file not found: {path}")
+
+        return cls.model_validate_json(path.read_text())
+
+    def to_file(self, path: Union[str, Path]) -> None:
+        """Save configuration to a file."""
+        path = Path(path)
+
+        if not path.parent.exists():
+            path.parent.mkdir(parents=True)
+
+        path.write_text(self.model_dump_json())
+
 
 def preprocess_audio_clip(
     clip: data.Clip,
@@ -105,6 +146,7 @@ def preprocess_audio_clip(
         spec,
         time=int(np.ceil(duration / config.spec_time_period)),
         frequency=config.spec_height,
+        dtype=np.float32,
     )