PEP 572: Add an appendix to clarify that there's no magical scoping (#714)

pep-0572.rst

@@ -1170,6 +1170,37 @@ Finally, let's nest two comprehensions.
         print(TARGET)
 
 
+Appendix C: No Changes to Scope Semantics
+=========================================
+
+Because it has been a point of confusion, note that nothing about Python's
+scoping semantics is changed.  Function-local scopes continue to be resolved
+at compile time, and to have indefinite temporal extent at run time ("full
+closures").  Example::
+
+    a = 42
+    def f():
+        # `a` is local to `f`
+        yield ((a := i) for i in range(3))
+        yield lambda: a + 100
+        print("done")
+
+Then::
+
+    >>> results = list(f()) # [genexp, lambda]
+    done
+    # The execution frame for f no longer exists in CPython,
+    # but f's locals live so long as they can still be referenced.
+    >>> list(map(type, results))
+    [<class 'generator'>, <class 'function'>]
+    >>> list(results[0])
+    [0, 1, 2]
+    >>> results[1]()
+    102
+    >>> a
+    42
+
+
 References
 ==========