\section{\module{symbol} ---
         Constants used with Python parse trees}

\declaremodule{standard}{symbol}
\modulesynopsis{Constants representing internal nodes of the parse tree.}
\sectionauthor{Fred L. Drake, Jr.}{fdrake@acm.org}


This module provides constants which represent the numeric values of
internal nodes of the parse tree.  Unlike most Python constants, these
use lower-case names.  Refer to the file \file{Grammar/Grammar} in the
Python distribution for the definitions of the names in the context of
the language grammar.  The specific numeric values which the names map
to may change between Python versions.

This module also provides one additional data object:


\begin{datadesc}{sym_name}
  Dictionary mapping the numeric values of the constants defined in
  this module back to name strings, allowing more human-readable
  representation of parse trees to be generated.
\end{datadesc}


\begin{seealso}
  \seemodule{parser}{The second example for the \refmodule{parser}
                     module shows how to use the \module{symbol}
                     module.}
\end{seealso}