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(python2.1-lib.info)linecache

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Random access to text lines
===========================

This manual section was written by Moshe Zadka
<moshez@zadka.site.co.il>.
This module provides random access to individual lines from text files.

The `linecache' module allows one to get any line from any file, while
attempting to optimize internally, using a cache, the common case where
many lines are read from a single file.  This is used by the
`traceback' module to retrieve source lines for inclusion in the
formatted traceback.

The `linecache' module defines the following functions:

`getline(filename, lineno)'
     Get line LINENO from file named FILENAME. This function will never
     throw an exception -- it will return `''' on errors (the
     terminating newline character will be included for lines that are
     found).

     If a file named FILENAME is not found, the function will look for
     it in the module  search path, `sys.path'.

`clearcache()'
     Clear the cache.  Use this function if you no longer need lines
     from files previously read using `getline()'.

`checkcache()'
     Check the cache for validity.  Use this function if files in the
     cache may have changed on disk, and you require the updated
     version.

Example:

     >>> import linecache
     >>> linecache.getline('/etc/passwd', 4)
     'sys:x:3:3:sys:/dev:/bin/sh\n'