[ENH] Add file extension validation and directory creation to save/load

Ensure correct `.gempy` extension when saving/loading models, raising errors for invalid or missing extensions. Added automatic creation of directories during save operations. Updated tests to reflect the enforced `.gempy` extension.

Author: Leguark

gempy/modules/serialization/save_load.py

@@ -1,9 +1,38 @@
 from ...core.data import GeoModel
 from ...core.data.encoders.converters import loading_model_from_binary
 from ...optional_dependencies import require_zlib
+import pathlib
+import os
 
 
 def save_model(model: GeoModel, path: str):
+    """
+    Save a GeoModel to a file with proper extension validation.
+    
+    Parameters:
+    -----------
+    model : GeoModel
+        The geological model to save
+    path : str
+        The file path where to save the model
+    
+    Raises:
+    -------
+    ValueError
+        If the file has an extension other than .gempy
+    """
+    # Define the valid extension for gempy models
+    VALID_EXTENSION = ".gempy"
+    
+    # Check if path has an extension
+    path_obj = pathlib.Path(path)
+    if path_obj.suffix:
+        # If extension exists but is not valid, raise error
+        if path_obj.suffix.lower() != VALID_EXTENSION:
+            raise ValueError(f"Invalid file extension: {path_obj.suffix}. Expected: {VALID_EXTENSION}")
+    else:
+        # If no extension, add the valid extension
+        path = str(path_obj) + VALID_EXTENSION
 
     model_json = model.model_dump_json(by_alias=True, indent=4)
 
@@ -13,14 +42,48 @@ def save_model(model: GeoModel, path: str):
 
     binary_file = _to_binary(model_json, compressed_binary)
 
-    # TODO: Add validation
+    # Create directory if it doesn't exist
+    directory = os.path.dirname(path)
+    if directory and not os.path.exists(directory):
+        os.makedirs(directory)
 
     with open(path, 'wb') as f:
         f.write(binary_file)
-        
 
+    return path  # Return the actual path used (helpful if extension was added)
 
 def load_model(path: str) -> GeoModel:
+    """
+    Load a GeoModel from a file with extension validation.
+    
+    Parameters:
+    -----------
+    path : str
+        Path to the gempy model file
+        
+    Returns:
+    --------
+    GeoModel
+        The loaded geological model
+        
+    Raises:
+    -------
+    ValueError
+        If the file doesn't have the proper .gempy extension
+    FileNotFoundError
+        If the file doesn't exist
+    """
+    VALID_EXTENSION = ".gempy"
+    
+    # Check if path has the valid extension
+    path_obj = pathlib.Path(path)
+    if not path_obj.suffix or path_obj.suffix.lower() != VALID_EXTENSION:
+        raise ValueError(f"Invalid file extension: {path_obj.suffix}. Expected: {VALID_EXTENSION}")
+    
+    # Check if file exists
+    if not os.path.exists(path):
+        raise FileNotFoundError(f"File not found: {path}")
+    
     with open(path, 'rb') as f:
         binary_file = f.read()
 
@@ -46,6 +109,4 @@ def _to_binary(header_json, body_) -> bytes:
     header_json_length = len(header_json_bytes)
     header_json_length_bytes = header_json_length.to_bytes(4, byteorder='little')
     file = header_json_length_bytes + header_json_bytes + body_
-    return file
-
-
+    return file

test/test_modules/test_serialize_model.py

@@ -49,10 +49,10 @@ def _validate_serialization(original_model, model_deserialized):
 
 def test_save_model_to_disk():
     model = gp.generate_example_model(ExampleModel.COMBINATION, compute_model=False)
-    save_model(model, "temp/test_save_model_to_disk.json")
+    save_model(model, "temp/test_save_model_to_disk.gempy")
 
     # Load the model from disk
-    loaded_model = load_model("temp/test_save_model_to_disk.json")
+    loaded_model = load_model("temp/test_save_model_to_disk.gempy")
     _validate_serialization(model, loaded_model)
 
     gp.compute_model(loaded_model)