Initial commit of Python queries and QL libraries.

python/ql/src/Exceptions/NotImplemented.qll

@@ -0,0 +1,11 @@
+
+import python
+
+/** Holds if `notimpl` refers to `NotImplemented` or `NotImplemented()` in the `raise` statement */
+predicate use_of_not_implemented_in_raise(Raise raise, Expr notimpl) {
+    notimpl.refersTo(theNotImplementedObject()) and
+    (
+        notimpl = raise.getException() or 
+        notimpl = raise.getException().(Call).getFunc()
+    )
+}