Issue #16863: Explain difference between text and 2.7 behavior.

diff --git a/Doc/howto/argparse.rst b/Doc/howto/argparse.rst
index f110a55bba7902ba031cadd91fced20ef58d6dac..f113c9847832d7c0719589d8e95e54178909149f 100644 (file)
--- a/Doc/howto/argparse.rst
+++ b/Doc/howto/argparse.rst
@@ -8,6 +8,8 @@ Argparse Tutorial
 
 This tutorial is intended to be a gentle introduction to :mod:`argparse`, the
 recommended command-line parsing module in the Python standard library.
+This was written for argparse in Python 3. A few details are different in 2.x,
+especially some exception messages, which were improved in 3.x.
 
 .. note::