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-rw-r--r--Doc/whatsnew/whatsnew20.tex16
1 files changed, 16 insertions, 0 deletions
diff --git a/Doc/whatsnew/whatsnew20.tex b/Doc/whatsnew/whatsnew20.tex
index 9211e64..7cc9913 100644
--- a/Doc/whatsnew/whatsnew20.tex
+++ b/Doc/whatsnew/whatsnew20.tex
@@ -556,6 +556,22 @@ added to the \module{sys} module. \code{sys.version_info} is a tuple
\var{level} is a string such as \code{"alpha"}, \code{"beta"}, or
\code{""} for a final release.
+Dictionaries have an odd new method, \method{setdefault(\var{key},
+\var{default})}, which behaves similarly to the existing
+\method{get()} method. However, if the key is missing,
+\method{setdefault()} both returns the value of \var{default} as
+\method{get()} would do, and also inserts it into the dictionary as
+the value for \var{key}. Thus, the following lines of code:
+
+\begin{verbatim}
+if dict.has_key( key ): return dict[key]
+else:
+ dict[key] = []
+ return dict[key]
+\end{verbatim}
+
+can be reduced to a single \code{return dict.setdefault(key, [])} statement.
+
% ======================================================================
\section{Extending/Embedding Changes}