Close bug 480337: Dict used before dicts explained. Added explanation
and examples of the dict() constructor.
diff --git a/Doc/tut/tut.tex b/Doc/tut/tut.tex
index 0dc53ef..0a4c95e 100644
--- a/Doc/tut/tut.tex
+++ b/Doc/tut/tut.tex
@@ -1843,8 +1843,6 @@
[12, 18]
>>> [3*x for x in vec if x < 2]
[]
->>> [{x: x**2} for x in vec]
-[{2: 4}, {4: 16}, {6: 36}]
>>> [[x,x**2] for x in vec]
[[2, 4], [4, 16], [6, 36]]
>>> [x, x**2 for x in vec] # error - parens required for tuples
@@ -2023,6 +2021,17 @@
1
\end{verbatim}
+The \function{dict()} contructor builds dictionaries directly from
+lists of key-value pairs stored as tuples. When the pairs form a
+pattern, list comprehensions can compactly specify the key-value list.
+
+\begin{verbatim}
+>>> dict([('sape', 4139), ('guido', 4127), ('jack', 4098)])
+{'sape': 4139, 'jack': 4098, 'guido': 4127}
+>>> dict([(x, x**2) for x in vec]) # use a list comprehension
+{2: 4, 4: 16, 6: 36}
+\end{verbatim}
+
\section{Looping Techniques \label{loopidioms}}