[3.13] gh-74929: PEP 667 general docs update (gh-119291)

* expand on What's New entry for PEP 667 (including porting notes)
* define 'optimized scope' as a glossary term
* cover comprehensions and generator expressions in locals() docs
* review all mentions of "locals" in documentation (updating if needed)
* review all mentions of "f_locals" in documentation (updating if needed)

(cherry picked from commit e870c852c0ea96fa4e4569e9c39c7ceb80ce858d)

Co-authored-by: Alyssa Coghlan <ncoghlan@gmail.com>

2 files changed, 10 insertions, 7 deletions

diff --git a/Lib/code.py b/Lib/code.py
index 9d12456..0c2fd29 100644
--- a/Lib/code.py
+++ b/Lib/code.py
@@ -25,10 +25,10 @@ class InteractiveInterpreter:
     def __init__(self, locals=None):
         """Constructor.
 
-        The optional 'locals' argument specifies the dictionary in
-        which code will be executed; it defaults to a newly created
-        dictionary with key "__name__" set to "__console__" and key
-        "__doc__" set to None.
+        The optional 'locals' argument specifies a mapping to use as the
+        namespace in which code will be executed; it defaults to a newly
+        created dictionary with key "__name__" set to "__console__" and
+        key "__doc__" set to None.
 
         """
         if locals is None:
diff --git a/Lib/pdb.py b/Lib/pdb.py
index e507a9b..0f791d7 100755
--- a/Lib/pdb.py
+++ b/Lib/pdb.py
@@ -392,9 +392,12 @@ class Pdb(bdb.Bdb, cmd.Cmd):
             self.tb_lineno[tb.tb_frame] = lineno
             tb = tb.tb_next
         self.curframe = self.stack[self.curindex][0]
-        # The f_locals dictionary is updated from the actual frame
-        # locals whenever the .f_locals accessor is called, so we
-        # cache it here to ensure that modifications are not overwritten.
+        # The f_locals dictionary used to be updated from the actual frame
+        # locals whenever the .f_locals accessor was called, so it was
+        # cached here to ensure that modifications were not overwritten. While
+        # the caching is no longer required now that f_locals is a direct proxy
+        # on optimized frames, it's also harmless, so the code structure has
+        # been left unchanged.
         self.curframe_locals = self.curframe.f_locals
         self.set_convenience_variable(self.curframe, '_frame', self.curframe)