Remove ClassLoader.py

Removed
-------

* Remove `ClassLoader.py`.

  `importlib`, in the Python standard library, is sufficient.
  This also reduces the number of licenses in use in the repo.

* Remove a reference to `ClassLoader.py` in the pre-commit config.

.pre-commit-config.yaml

@@ -13,14 +13,11 @@
 # you'll have an opportunity to review and stage the changes made by the
 # hooks.
 #
-# To format the files in this repo, you can run this command (but be
-# aware that pyupgrade will need to be run three times because there is
-# a specific line in ClassLoader.py that pyupgrade incrementally
-# updates).
+# To format all files in this repo, you can run this command
+# (but be aware that sometimes the command must be run multiple times
+# because pyupgrade has several stepping-stone upgrades to apply).
 #
 # pre-commit run -a
-# pre-commit run -a
-# pre-commit run -a
 #
 # I strongly recommend enabling pre-commit.ci, which -- like coveralls
 # -- will automatically run an additional action against incoming PRs.

src/smartcard/reader/ReaderFactory.py

@@ -6,10 +6,6 @@
 Thinking in Python, Bruce Eckel,
 http://mindview.net/Books/TIPython
 
-The code to instantiate the reader Factory() has
-been updated to dynamically load the module with
-Robert Brewer ClassLoader.py.
-
 Copyright 2001-2012 gemalto
 Author: Jean-Daniel Aussel, mailto:[email protected]
 
@@ -30,7 +26,8 @@
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 """
 
-from smartcard.ClassLoader import get_class
+import importlib
+
 from smartcard.pcsc.PCSCReader import PCSCReader
 
 
@@ -42,14 +39,19 @@ class ReaderFactory:
 
     # A Template Method:
     @staticmethod
-    def createReader(clazz, readername):
+    def createReader(clazz: str, readername: str):
         """Static method to create a reader from a reader clazz.
 
         @param clazz:      the reader class name
         @param readername: the reader name
         """
-        if not clazz in ReaderFactory.factories:
-            ReaderFactory.factories[clazz] = get_class(clazz).Factory()
+
+        if clazz not in ReaderFactory.factories:
+            module_name, _, class_name = clazz.rpartition(".")
+            imported_module = importlib.import_module(module_name)
+            imported_class = getattr(imported_module, class_name)
+            ReaderFactory.factories[clazz] = imported_class.Factory()
+
         return ReaderFactory.factories[clazz].create(readername)
 
     @staticmethod