load SALT_SOLVENT_PATH using datamol_data_file_path fxn

datamol/data/__init__.py

@@ -13,6 +13,7 @@
 
 import sys
 import io
+import functools
 
 try:
     import importlib.resources as importlib_resources
@@ -26,6 +27,15 @@
 from ..convert import from_df
 from ..convert import render_mol_df
 
+@functools.lru_cache()
+def datamol_data_file_path(filename: str, dm_module: str = "datamol.data") -> str:
+    if sys.version_info < (3, 9, 0):
+        with importlib_resources.path("datamol.data", filename) as p:
+            data_path = p
+    else:
+        data_path = importlib_resources.files(dm_module).joinpath(filename)
+
+    return str(data_path)
 
 def open_datamol_data_file(
     filename: str,

datamol/mol.py

@@ -45,8 +45,7 @@
 AROMATIC_BOND = Chem.rdchem.BondType.AROMATIC
 DATIVE_BOND = Chem.rdchem.BondType.DATIVE
 UNSPECIFIED_BOND = Chem.rdchem.BondType.UNSPECIFIED
-with datamol.data.open_datamol_data_file("salts_solvents.smi") as file_obj:
-    SALT_SOLVENT_PATH = file_obj.name
+SALT_SOLVENT_PATH = datamol.data.datamol_data_file_path("salts_solvents.smi")
 SALT_SOLVENT_REMOVER = SaltRemover(defnFilename=SALT_SOLVENT_PATH)