\section{\module{linecache} ---         Random access to text lines} \declaremodule{standard}{linecache}\sectionauthor{Moshe Zadka}{moshez@zadka.site.co.il}\modulesynopsis{This module provides random access to individual lines                from text files.}  The \module{linecache} module allows one to get any line from any file,while attempting to optimize internally, using a cache, the common casewhere many lines are read from a single file.  This is used by the\refmodule{traceback} module to retrieve source lines for inclusion in the formatted traceback. The \module{linecache} module defines the following functions: \begin{funcdesc}{getline}{filename, lineno\optional{, module_globals}}Get line \var{lineno} from file named \var{filename}. This functionwill never throw an exception --- it will return \code{''} on errors(the terminating newline character will be included for lines that arefound). If a file named \var{filename} is not found, the function will lookfor it in the module\indexiii{module}{search}{path} search path,\code{sys.path}, after first checking for a \pep{302} \code{__loader__}in \var{module_globals}, in case the module was imported from a zipfileor other non-filesystem import source.  \versionadded[The \var{module_globals} parameter was added]{2.5}\end{funcdesc} \begin{funcdesc}{clearcache}{}Clear the cache.  Use this function if you no longer need lines fromfiles previously read using \function{getline()}.\end{funcdesc} \begin{funcdesc}{checkcache}{\optional{filename}}Check the cache for validity.  Use this function if files in the cache may have changed on disk, and you require the updated version.  If\var{filename} is omitted, it will check all the entries in the cache.\end{funcdesc} Example: \begin{verbatim}>>> import linecache>>> linecache.getline('/etc/passwd', 4)'sys:x:3:3:sys:/dev:/bin/sh\n'\end{verbatim}