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52 lines
1.8 KiB
ReStructuredText
52 lines
1.8 KiB
ReStructuredText
:mod:`linecache` --- Random access to text lines
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================================================
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.. module:: linecache
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:synopsis: This module provides random access to individual lines from text files.
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.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>
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**Source code:** :source:`Lib/linecache.py`
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--------------
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The :mod:`linecache` module allows one to get any line from any file, while
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attempting to optimize internally, using a cache, the common case where many
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lines are read from a single file. This is used by the :mod:`traceback` module
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to retrieve source lines for inclusion in the formatted traceback.
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The :mod:`linecache` module defines the following functions:
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.. function:: getline(filename, lineno, module_globals=None)
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Get line *lineno* from file named *filename*. This function will never raise an
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exception --- it will return ``''`` on errors (the terminating newline character
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will be included for lines that are found).
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.. index:: triple: module; search; path
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If a file named *filename* is not found, the function will look for it in the
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module search path, ``sys.path``, after first checking for a :pep:`302`
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``__loader__`` in *module_globals*, in case the module was imported from a
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zipfile or other non-filesystem import source.
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.. function:: clearcache()
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Clear the cache. Use this function if you no longer need lines from files
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previously read using :func:`getline`.
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.. function:: checkcache(filename=None)
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Check the cache for validity. Use this function if files in the cache may have
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changed on disk, and you require the updated version. If *filename* is omitted,
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it will check all the entries in the cache.
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Example::
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>>> import linecache
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>>> linecache.getline('/etc/passwd', 4)
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'sys:x:3:3:sys:/dev:/bin/sh\n'
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