Update error message in ParticleFile writing (#2698)

* Update error message in ParticleFile writing

* Add test

Author: VeckoTheGecko

src/parcels/_core/particlefile.py

@@ -106,11 +106,13 @@ def __init__(
 
         if path.exists():
             if mode is None:
-                raise ValueError(f"{path=!r} already exists. Use mode='w' or use a new path.")
+                msg = f"Path '{path}' already exists. Use mode='w' or use a new path."
+                raise ValueError(msg)
             if mode == "w":
                 path.unlink()
         if not path.parent.exists():
-            raise ValueError(f"Folder location for {path=!r} does not exist. Create the folder location first.")
+            msg = f"Folder location for '{path} does not exist. Create the folder location first."
+            raise ValueError(msg)
 
         self.metadata = {}
 

tests/test_particlefile.py

@@ -431,6 +431,18 @@ def test_particlefile_init_existing_path_modes(fieldset, tmp_parquet):
     assert len(df_first) == len(df_overwrite)
 
 
+def test_particlefile_init_existing_path_no_mode(tmp_parquet):
+    tmp_parquet.touch()
+    with pytest.raises(ValueError, match="already exists"):
+        ParticleFile(tmp_parquet, outputdt=np.timedelta64(1, "s"))
+
+
+def test_particlefile_init_nonexistent_parent(tmp_path):
+    path = tmp_path / "nonexistent_dir" / "file.parquet"
+    with pytest.raises(ValueError, match="does not exist"):
+        ParticleFile(path, outputdt=np.timedelta64(1, "s"))
+
+
 def test_particlefile_init_invalid_mode(tmp_parquet):
     with pytest.raises(ValueError, match="Invalid mode value"):
         ParticleFile(tmp_parquet, outputdt=np.timedelta64(1, "s"), mode="something-else")