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[, module_globals]) |
-
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 , after first checking for a PEP 302 __loader__
in module_globals, in case the module was imported from a zipfile
or other non-filesystem import source.
New in version 2.5:
The module_globals parameter was added.
-
Clear the cache. Use this function if you no longer need lines from
files previously read using getline().
-
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
filename is omitted, it will check all the entries in the cache.
Example:
>>> import linecache
>>> linecache.getline('/etc/passwd', 4)
'sys:x:3:3:sys:/dev:/bin/sh\n'
Release 2.5.2, documentation updated on 21st February, 2008.
See About this document... for information on suggesting changes.
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