check whether paths exist for import

corrlib/toml.py

@@ -158,6 +158,10 @@ def import_toml(path: Path, file: str, copy_file: bool=True) -> None:
     copy_file: bool, optional
         Whether the toml-files will be copied into the library. Default is True.
     """
+    if not os.path.exists(path):
+        raise FileNotFoundError(f"Corrlib path {path} does not exist.")
+    if not os.path.exists(file):
+        raise FileNotFoundError(f".toml-file {file} does not exist.")
     print("Import project as decribed in " + file)
     with open(file, 'rb') as fp:
         toml_dict = toml.load(fp)