Yurttas/PL/SL/python/docs/core-python-programming/doc/20/lib/module-linecache.html
3.10 linecache -- Random access to text lines
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\012'
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