diff --git a/tools/python/jwutils/misc.py b/tools/python/jwutils/misc.py
index 8800211..cf6d19f 100644
--- a/tools/python/jwutils/misc.py
+++ b/tools/python/jwutils/misc.py
@@ -1,6 +1,8 @@
 import os, errno
 import atexit
 import tempfile
+import inspect
+from jwutils import log
 
 _tmpfiles = set()
 
@@ -46,4 +48,18 @@ def object_builtin_name(o, full=True): # export
         return o.__class__.__name__  # Avoid reporting __builtin__
     return module + '.' + o.__class__.__name__
 
+def get_derived_classes(mod, base): # export
+    members = inspect.getmembers(mod, inspect.isclass)
+    r = []
+    for name, c in members:
+        log.slog(log.DEBUG, "found ", name)
+        if inspect.isabstract(c):
+            log.slog(log.DEBUG, "  is abstract")
+            continue
+        if not base in inspect.getmro(c):
+            log.slog(log.DEBUG, "  is not derived from", base, "only", inspect.getmro(c))
+            continue
+        r.append(c)
+    return r
+
 atexit.register(_cleanup)