Fix theochem#173 by updating import-resources API

This arises from pull-request theochem#174. Rather than using an older
version of import-resources. This fixed the issue to the current
API

src/grid/angular.py

@@ -68,7 +68,7 @@
 from bisect import bisect_left
 
 import numpy as np
-from importlib_resources import path
+from importlib_resources import files
 
 from grid.basegrid import Grid
 
@@ -554,8 +554,7 @@ def _load_precomputed_angular_grid(degree: int, size: int, use_spherical: bool):
             raise ValueError(f"Given size={size} is not supported, choose from {npoints}")
         # load npz file corresponding to the given degree & size
         filename = f"{type}_{degree}_{size}.npz"
-        with path(file_path, filename) as npz_file:
-            data = np.load(npz_file)
+        data = np.load(files(file_path).joinpath(filename)) 
         if len(data["weights"]) == 1:
             return data["points"], np.ones(len(data["points"])) * data["weights"]
         return data["points"], data["weights"]

src/grid/atomgrid.py

@@ -22,7 +22,7 @@
 from typing import Union
 
 import numpy as np
-from importlib_resources import path
+from importlib_resources import files
 from scipy.interpolate import CubicSpline
 from scipy.spatial.transform import Rotation as R
 
@@ -173,11 +173,10 @@ def from_preset(
         center = np.zeros(3, dtype=float) if center is None else np.asarray(center, dtype=float)
         cls._input_type_check(rgrid, center)
         # load radial points and
-        with path("grid.data.prune_grid", f"prune_grid_{preset}.npz") as npz_file:
-            data = np.load(npz_file)
-            # load predefined_radial sectors and num_of_points in each sectors
-            rad = data[f"{atnum}_rad"]
-            npt = data[f"{atnum}_npt"]
+        data = np.load(files("grid.data.prune_grid").joinpath(f"prune_grid_{preset}.npz"))
+        # load predefined_radial sectors and num_of_points in each sectors
+        rad = data[f"{atnum}_rad"]
+        npt = data[f"{atnum}_npt"]
 
         degs = AngularGrid.convert_angular_sizes_to_degrees(npt, use_spherical)
         rad_degs = AtomGrid._find_l_for_rad_list(rgrid.points, rad, degs)

src/grid/hirshfeld.py

@@ -21,7 +21,7 @@
 
 
 import numpy as np
-from importlib_resources import path
+from importlib_resources import files
 from scipy.interpolate import CubicSpline
 
 
@@ -34,8 +34,7 @@ def __init__(self):
     @staticmethod
     def _load_npz_proatom(num):
         """Return radial grid points and neutral density for a given atomic number."""
-        with path("grid.data.proatoms", f"a{num:03d}.npz") as fname:
-            data = np.load(fname)
+        data = np.load(files("grid.data.proatoms").joinpath(f"a{num:03d}.npz"))
         return data["r"], data["dn"]
 
     @staticmethod