Use the importlib.resources backport on Python < 3.7

Author: dstufft

certifi/core.py

@@ -11,13 +11,9 @@
 try:
     from importlib.resources import read_text
 except ImportError:
-    # This fallback will work for Python versions prior to 3.7 that lack the
-    # importlib.resources module but relies on the existing `where` function
-    # so won't address issues with environments like PyOxidizer that don't set
-    # __file__ on modules.
-    def read_text(_module, _path, encoding="ascii"):
-        with open(where(), "r", encoding=encoding) as data:
-            return data.read()
+    # Use the backport of importlib.resources for versions of Python that
+    # don't have importlib.resources
+    from importlib_resources import read_text
 
 
 def where():

setup.py

@@ -57,4 +57,5 @@
         'Documentation': 'https://certifiio.readthedocs.io/en/latest/',
         'Source': 'https://github.com/certifi/python-certifi',
     },
+    extras_require={":python_version < '3.7'": ["importlib-resources"],},
 )