Improve the find_profile_data function for Python3.9+

The `importlib.resources` lib that we use in this function has changed its API. Our function would still work but raise a deprecation warning. There is a risk that the functions we require would be deleted at some point; this commit makes our function future-proof (at least for the next versions).
We try to import the most recent functions; if it does not work, we assume we are on an older version and resort to the previous API (for which there will be no deprecation warning at this point).

Python 3.7 is no longer supported by the Python community; Python 3.8 will reach end-of-life on 2024-10. At some point, our function could drop this "backup" import for older versions; but for now, they may still be used.

smartgrid/make_env.py

@@ -35,13 +35,6 @@ def find_profile_data(dataset: str, filename: str) -> str:
     :py:mod:`importlib.resources` is used to get a path to the file through the
     package.
 
-    This function may raise a ``DeprecationWarning`` when accessing
-    files through the package on Python3.11+. It is due to relying on the
-    :py:func:`importlib.resources.path` function, which is deprecated since
-    Python 3.11. As we support up to Python 3.7, and as the function is
-    only available since Python 3.9, it is still used instead of the more
-    recent :py:func:`importlib.resources.files`.
-
     :param dataset: The name of the folder containing the desired file, within
         the ``data`` folder. For example, ``openei`` to access the OpenEI
         dataset. This dataset cannot be nested, e.g., ``dataset/subdataset``
@@ -61,20 +54,25 @@ def find_profile_data(dataset: str, filename: str) -> str:
         # Hard mode: need to access it through the package (importlib).
         # Also, importlib returns a context, so we need to get the path
         # and exit the context when Python terminates.
-        import importlib_resources
         from contextlib import ExitStack
         import atexit
+        # Depending on the Python version, there are two ways to use importlib.
+        try:
+            # Python 3.9+
+            from importlib.resources import files, as_file
+            data = files('smartgrid.data').joinpath(dataset, filename)
+            ctx = as_file(data)
+        except ImportError:
+            # Python 3.7 and 3.8
+            from importlib.resources import path
+            ctx = path(f'smartgrid.data.{dataset}', filename)
         # Handle the context
         file_manager = ExitStack()
         # Close the context when Python terminates
         atexit.register(file_manager.close)
-        # `path` is deprecated since Python3.9, but we support up to 3.7,
-        # so we still use `path`. There is not much benefit to check whether
-        # the new `files` API is available and use it instead.
-        ctx = importlib_resources.path(f'smartgrid.data.{dataset}', filename)
-        path = file_manager.enter_context(ctx)
+        data_file_path = file_manager.enter_context(ctx)
         # Convert the PosixPath to a simple str for easier usage.
-        return str(path)
+        return str(data_file_path)
 
 
 def make_basic_smartgrid(