From 3214a01d2789d59d7933ac38c683b18296d73b66 Mon Sep 17 00:00:00 2001 From: Georg Brandl Date: Tue, 1 Jul 2008 20:50:02 +0000 Subject: [PATCH] #1410739: add a footnote about "is" and "unusual" behavior. --- Doc/reference/expressions.rst | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst index e393661735f..c815c0ef894 100644 --- a/Doc/reference/expressions.rst +++ b/Doc/reference/expressions.rst @@ -1113,7 +1113,7 @@ The operator :keyword:`not in` is defined to have the inverse true value of The operators :keyword:`is` and :keyword:`is not` test for object identity: ``x is y`` is true if and only if *x* and *y* are the same object. ``x is not y`` -yields the inverse truth value. +yields the inverse truth value. [#]_ .. _booleans: @@ -1352,3 +1352,7 @@ groups from right to left). only, but this caused surprises because people expected to be able to test a dictionary for emptiness by comparing it to ``{}``. +.. [#] Due to automatic garbage-collection, free lists, and the dynamic nature of + descriptors, you may notice seemingly unusual behaviour in certain uses of + the :keyword:`is` operator, like those involving comparisons between instance + methods, or constants. Check their documentation for more info.