\section{Standard Module \module{bisect}}

\stmodindex{bisect}

\label{module-bisect}

This module provides support for maintaining a list in sorted order

without having to sort the list after each insertion. For long lists

of items with expensive comparison operations, this can be an

improvement over the more common approach. The module is called

\module{bisect} because it uses a basic bisection algorithm to do its

work. The source code may be used a useful reference for a working

example of the algorithm (i.e., the boundary conditions are already

right!).

The following functions are provided:

\begin{funcdesc}{bisect}{list, item\optional{, lo\optional{, hi}}}

Locate the proper insertion point for \var{item} in \var{list} to

maintain sorted order. The parameters \var{lo} and \var{hi} may be

used to specify a subset of the list which should be considered. The

return value is suitable for use as the first parameter to

\code{\var{list}.insert()}.

\end{funcdesc}

\begin{funcdesc}{insort}{list, item\optional{, lo\optional{, hi}}}

Insert \var{item} in \var{list} in sorted order. This is equivalent

to \code{\var{list}.insert(bisect.bisect(\var{list}, \var{item},

\var{lo}, \var{hi}), \var{item})}.

\end{funcdesc}

\subsection{Example}

\nodename{bisect-example}

The \function{bisect()} function is generally useful for categorizing

numeric data. This example uses \function{bisect()} to look up a

letter grade for an exam total (say) based on a set of ordered numeric

breakpoints: 85 and up is an `A', 75..84 is a `B', etc.

\begin{verbatim}

\end{verbatim}