protect importlib usage

pyproject.toml

@@ -38,6 +38,7 @@ dependencies=[
     "biocommons.seqrepo >= 0.6.5",
     "bioutils >= 0.4.0,<1.0",
     "configparser >= 3.3.0",
+    "importlib_resources",
     "ipython",
     "parsley",
     "psycopg2",

src/hgvs/config.py

@@ -31,7 +31,10 @@
 import re
 from configparser import ConfigParser, ExtendedInterpolation
 from copy import copy
-from importlib import resources
+try:
+    from importlib.resources import files as resources_files
+except ImportError:
+    from importlib_resources import files as resources_files
 
 logger = logging.getLogger(__name__)
 
@@ -115,6 +118,6 @@ def _val_xform(v):
 
 
 _default_config = Config()
-_default_config.read_stream(resources.files(__package__) / "_data" / "defaults.ini")
+_default_config.read_stream(resources_files(__package__) / "_data" / "defaults.ini")
 
 global_config = copy(_default_config)

tests/test_hgvs_grammar_full.py

@@ -4,7 +4,10 @@
 import re
 import unittest
 from sys import version_info
-from importlib import resources
+try:
+    from importlib.resources import files as resources_files
+except ImportError:
+    from importlib_resources import files as resources_files
 
 #
 # Tests of the grammar
@@ -51,7 +54,7 @@ def test_parser_test_completeness(self):
         """ensure that all rules in grammar have tests"""
 
         grammar_rule_re = re.compile(r"^(\w+)")
-        grammar_fn = resources.files("hgvs") / "_data" / "hgvs.pymeta"
+        grammar_fn = resources_files("hgvs") / "_data" / "hgvs.pymeta"
         with open(grammar_fn, "r") as f:
             grammar_rules = set(r.group(1) for r in filter(None, map(grammar_rule_re.match, f)))