SF bug #1249837: container methods raise KeyError not IndexError
Minor clarification.
diff --git a/Doc/ref/ref3.tex b/Doc/ref/ref3.tex
index 6754c27..46388b2 100644
--- a/Doc/ref/ref3.tex
+++ b/Doc/ref/ref3.tex
@@ -1658,6 +1658,8 @@
raised; if of a value outside the set of indexes for the sequence
(after any special interpretation of negative values),
\exception{IndexError} should be raised.
+For mapping types, if \var{key} is missing (not in the container),
+\exception{KeyError} should be raised.
\note{\keyword{for} loops expect that an
\exception{IndexError} will be raised for illegal indexes to allow
proper detection of the end of the sequence.}