Settings
########

Pelican is configurable thanks to a settings file you can pass to the command
line::

    pelican content -s path/to/your/pelicanconf.py

If you used the ``pelican-quickstart`` command, your primary settings file will
be named ``pelicanconf.py`` by default.

You can also specify settings via ``-e`` / ``--extra-settings`` option
flags. It will override default settings as well as any defined within the
setting file. Note that values must follow JSON notation::

    pelican content -e SITENAME='"A site"' READERS='{"html": null}' CACHE_CONTENT=true

Environment variables can also be used here but must be escaped appropriately::

    pelican content -e API_KEY=''\"$API_KEY\"''

.. note::

   When experimenting with different settings (especially the metadata ones)
   caching may interfere and the changes may not be visible. In such cases
   disable caching with ``LOAD_CONTENT_CACHE = False`` or use the
   ``--ignore-cache`` command-line switch.

Settings are configured in the form of a Python module (a file). There is an
`example settings file
<https://raw.githubusercontent.com/getpelican/pelican/main/samples/pelican.conf.py>`_
available for reference.

To see a list of current settings in your environment, including both default
and any customized values, run the following command (append one or more
specific setting names as arguments to see values for those settings only)::

    pelican --print-settings

All the setting identifiers must be set in all-caps, otherwise they will not be
processed. Setting values that are numbers (5, 20, etc.), booleans (True,
False, None, etc.), dictionaries, or tuples should *not* be enclosed in
quotation marks. All other values (i.e., strings) *must* be enclosed in
quotation marks.

Unless otherwise specified, settings that refer to paths can be either absolute
or relative to the configuration file. The settings you define in the
configuration file will be passed to the templates, which allows you to use
your settings to add site-wide content.

Here is a list of settings for Pelican:


Basic settings
==============

.. data:: USE_FOLDER_AS_CATEGORY

   When you don't specify a category in your post metadata, set this setting to
   ``True``, and organize your articles in subfolders, the subfolder will
   become the category of your post. If set to ``False``, ``DEFAULT_CATEGORY``
   will be used as a fallback. The default is ``True``.

.. data:: DEFAULT_CATEGORY

   The default category to fall back on. The default is ``"misc"``.

.. data:: DISPLAY_PAGES_ON_MENU

   Whether to display pages on the menu of the template. Templates may or may
   not honor this setting. The default is ``True``.

.. data:: DISPLAY_CATEGORIES_ON_MENU

   Whether to display categories on the menu of the template. Templates may or
   not honor this setting. The default is ``True``.

.. data:: DOCUTILS_SETTINGS

   Extra configuration settings for the docutils publisher (applicable only to
   reStructuredText). See `Docutils Configuration`_ settings for more details.
   The default is ``{}`` with no extra configuration settings.

.. data:: DELETE_OUTPUT_DIRECTORY

   Delete the output directory, and **all** of its contents, before generating
   new files. This can be useful in preventing older, unnecessary files from
   persisting in your output. However, **this is a destructive setting and
   should be handled with extreme care.** The default is ``False``.

.. data:: OUTPUT_RETENTION

   A list of filenames that should be retained and not deleted from the output
   directory. One use case would be the preservation of version control data.

   Example::

      OUTPUT_RETENTION = [".hg", ".git", ".bzr"]

   The default is ``[]``.

.. data:: JINJA_ENVIRONMENT

   A dictionary of custom Jinja2 environment variables you want to use. This
   also includes a list of extensions you may want to include. See `Jinja
   Environment documentation`_. The default is
   ``{"extensions": [], "trim_blocks": True, "lstrip_blocks": True}``.

.. data:: JINJA_FILTERS

   A dictionary of custom Jinja2 filters you want to use.  The dictionary
   should map the filtername to the filter function.

   Example::

    import sys
    sys.path.append("to/your/path")

    from custom_filter import urlencode_filter
    JINJA_FILTERS = {"urlencode": urlencode_filter}

   See: `Jinja custom filters documentation`_. The default is ``{}``.

.. data:: JINJA_GLOBALS

   A dictionary of custom objects to map into the Jinja2 global environment
   namespace. The dictionary should map the global name to the global
   variable/function. See: `Jinja global namespace documentation`_. The
   default is ``{}``.

.. data:: JINJA_TESTS

   A dictionary of custom Jinja2 tests you want to use. The dictionary should
   map test names to test functions. See: `Jinja custom tests documentation`_.
   The default is ``{}``.

.. data:: LOG_FILTER

   A list of tuples containing the logging level (up to ``warning``) and the
   message to be ignored.

   Example::

      LOG_FILTER = [(logging.WARN, "TAG_SAVE_AS is set to False")]

   The default is ``[]``.

.. data:: READERS

   A dictionary of file extensions / Reader classes for Pelican to process or
   ignore.

   For example, to avoid processing .html files, set::

      READERS = {"html": None}

   To add a custom reader for the ``foo`` extension, set::

      READERS = {"foo": FooReader}

   The default is ``{}``.

.. data:: IGNORE_FILES

   A list of Unix glob patterns. Files and directories matching any of these patterns
   or any of the commonly hidden files and directories set by ``watchfiles.DefaultFilter``
   will be ignored by the processor. For example, the default ``["**/.*"]`` will
   ignore "hidden" files and directories, and ``["__pycache__"]`` would ignore
   Python 3's bytecode caches.

   For a full list of the commonly hidden files set by ``watchfiles.DefaultFilter``,
   please refer to the `watchfiles documentation`_.

   The default is ``["**/.*"]``.

.. data:: MARKDOWN

   Extra configuration settings for the Markdown processor. Refer to the Python
   Markdown documentation's `Options section
   <https://python-markdown.github.io/reference/#markdown>`_ for a complete
   list of supported options. The ``extensions`` option will be automatically
   computed from the ``extension_configs`` option.

   The default is::

        MARKDOWN = {
            "extension_configs": {
                "markdown.extensions.codehilite": {"css_class": "highlight"},
                "markdown.extensions.extra": {},
                "markdown.extensions.meta": {},
            },
            "output_format": "html5",
        }

   .. Note::
      The dictionary defined in your settings file will replace this default
      one.

.. data:: OUTPUT_PATH

   Where to output the generated files. This should correspond to your web
   server's virtual host root directory.

   The default is ``"output"``.

.. data:: PATH

   Path to content directory to be processed by Pelican. If undefined, and
   content path is not specified via an argument to the ``pelican`` command,
   Pelican will default to ``"."``, the current working directory.

.. data:: PAGE_PATHS

   A list of directories and files to look at for pages, relative to ``PATH``.
   The default is ``["pages"]``.

.. data:: PAGE_EXCLUDES

   A list of directories to exclude when looking for pages in addition to
   ``ARTICLE_PATHS``. The default is ``[]``.

.. data:: ARTICLE_PATHS

   A list of directories and files to look at for articles, relative to
   ``PATH``. The default is ``[""]``.

.. data:: ARTICLE_EXCLUDES

   A list of directories to exclude when looking for articles in addition to
   ``PAGE_PATHS``. The default is ``[]``.

.. data:: OUTPUT_SOURCES

   Set to True if you want to copy the articles and pages in their original
   format (e.g. Markdown or reStructuredText) to the specified ``OUTPUT_PATH``.
   The default is ``False``.

.. data:: OUTPUT_SOURCES_EXTENSION

   Controls the extension that will be used by the SourcesGenerator.  Defaults
   to ``.text``. If not a valid string the default value will be used. The
   default is ``".text"``.

.. data:: PLUGINS

   The list of plugins to load. See :ref:`plugins`. The default is ``None``.

.. data:: PLUGIN_PATHS

   A list of directories where to look for plugins. See :ref:`plugins`. The
   default is ``[]``.

.. data:: SITENAME

   Your site's name. The default is ``"A Pelican Blog"``.

.. data:: SITEURL

   Base URL of your web site. Not defined by default, so it is best to specify
   your SITEURL; if you do not, feeds will not be generated with
   properly-formed URLs. If your site is available via HTTPS, this setting
   should begin with ``https://`` — otherwise use ``http://``. Then append your
   domain, with no trailing slash at the end. Example: ``SITEURL =
   "https://example.com"``

   The default is ``""``, the blank string.

.. data:: STATIC_PATHS

   A list of directories (relative to ``PATH``) in which to look for static
   files. Such files will be copied to the output directory without
   modification. Articles, pages, and other content source files will normally
   be skipped, so it is safe for a directory to appear both here and in
   ``PAGE_PATHS`` or ``ARTICLE_PATHS``.  Pelican's default settings include the
   "images" directory here. The default is ``["images"]``.

.. data:: STATIC_EXCLUDES

   A list of directories to exclude when looking for static files. The default
   is ``[]``.

.. data:: STATIC_EXCLUDE_SOURCES

   If set to False, content source files will not be skipped when copying files
   found in ``STATIC_PATHS``. This setting is for backward compatibility with
   Pelican releases before version 3.5.  It has no effect unless
   ``STATIC_PATHS`` contains a directory that is also in ``ARTICLE_PATHS`` or
   ``PAGE_PATHS``. If you are trying to publish your site's source files,
   consider using the ``OUTPUT_SOURCES`` setting instead. The default is
   ``True``.

.. data:: STATIC_CREATE_LINKS

   Create links instead of copying files. If the content and output directories
   are on the same device, then create hard links.  Falls back to symbolic
   links if the output directory is on a different filesystem. If symlinks are
   created, don't forget to add the ``-L`` or ``--copy-links`` option to rsync
   when uploading your site. The default is ``False``.

.. data:: STATIC_CHECK_IF_MODIFIED

   If set to ``True``, and ``STATIC_CREATE_LINKS`` is ``False``, compare mtimes
   of content and output files, and only copy content files that are newer than
   existing output files. The default is ``False``.

.. data:: TYPOGRIFY

   If set to ``True``, several typographical improvements will be incorporated into
   the generated HTML via the `Typogrify
   <https://pypi.org/project/typogrify/>`_ library, which can be installed
   via: ``python -m pip install typogrify``. The default is ``False``.

.. data:: TYPOGRIFY_IGNORE_TAGS

   A list of tags for Typogrify to ignore. By default Typogrify will ignore
   ``pre`` and ``code`` tags. This requires that Typogrify version 2.0.4 or
   later is installed. The default is ``[]``.

.. data:: TYPOGRIFY_OMIT_FILTERS

   A list of Typogrify filters to skip. Allowed values are: ``"amp"``,
   ``"smartypants"``, ``"caps"``, ``"initial_quotes"``, ``"widont"``. By
   default, no filter is omitted (in other words, all filters get applied). This
   setting requires that Typogrify version 2.1.0 or later is installed. The
   default is ``[]``.

.. data:: TYPOGRIFY_DASHES

   This setting controls how Typogrify sets up the Smartypants filter to
   interpret multiple dash/hyphen/minus characters. A single ASCII dash
   character (``-``) is always rendered as a hyphen. The ``default`` setting
   does not handle en-dashes and converts double-hyphens into em-dashes. The
   ``oldschool`` setting renders both en-dashes and em-dashes when it sees two
   (``--``) and three (``---``) hyphen characters, respectively. The
   ``oldschool_inverted`` setting turns two hyphens into an em-dash and three
   hyphens into an en-dash. The default is ``"default"``.

.. data:: SUMMARY_MAX_LENGTH

   When creating a short summary of an article, this will be the default length
   (measured in words) of the text created.  This only applies if your content
   does not otherwise specify a summary. Setting to ``None`` will cause the
   summary to be a copy of the original content. The default is ``50``.

.. data:: SUMMARY_MAX_PARAGRAPHS

   When creating a short summary of an article, this will be the number of
   paragraphs to use as the summary. This only applies if your content
   does not otherwise specify a summary. Setting to ``None`` will cause the
   summary to use the whole text (up to ``SUMMARY_MAX_LENGTH``) instead of just
   the first N paragraphs. The default is ``None``.

.. data:: SUMMARY_END_SUFFIX

   When creating a short summary of an article and the result was truncated to
   match the required word length, this will be used as the truncation suffix.
   The default is ``"…"``.

.. data:: WITH_FUTURE_DATES

   If disabled, content with dates in the future will get a default status of
   ``draft``. See :ref:`reading_only_modified_content` for caveats. The default
   is ``True``.

.. data:: INTRASITE_LINK_REGEX

   Regular expression that is used to parse internal links. Default syntax when
   linking to internal files, tags, etc., is to enclose the identifier, say
   ``filename``, in ``{}`` or ``||``. Identifier between ``{`` and ``}`` goes
   into the ``what`` capturing group.  For details see
   :ref:`ref-linking-to-internal-content`. The default is
   ``"[{|](?P<what>.*?)[|}]"``.

.. data:: PYGMENTS_RST_OPTIONS

   A list of default Pygments settings for your reStructuredText code blocks.
   See :ref:`internal_pygments_options` for a list of supported options. The
   default is ``{}``.

.. data:: CACHE_CONTENT

   If ``True``, saves content in caches.  See
   :ref:`reading_only_modified_content` for details about caching. The default
   is ``False``.

.. data:: CONTENT_CACHING_LAYER

   If set to ``"reader"``, save only the raw content and metadata returned by
   readers. If set to ``"generator"``, save processed content objects. The
   default is ``"reader"``.

.. data:: CACHE_PATH

   Directory in which to store cache files. The default is ``"cache"``.

.. data:: GZIP_CACHE

   If ``True``, use gzip to (de)compress the cache files. The default is
   ``True``.

.. data:: CHECK_MODIFIED_METHOD

   Controls how files are checked for modifications.

   - If set to ``"mtime"``, the modification time of the file is
     checked.
   - If set to a name of a function provided by the ``hashlib``
     module, e.g. ``"md5"``, the file hash is checked.

   The default is ``"mtime"``.

.. data:: LOAD_CONTENT_CACHE

   If ``True``, load unmodified content from caches. The default is ``False``.

.. data:: FORMATTED_FIELDS

   A list of metadata fields containing reST/Markdown content to be parsed and
   translated to HTML. The default is ``["summary"]``.

.. data:: PORT

   The TCP port to serve content from the output folder via HTTP when pelican
   is run with ``--listen``. The default is ``8000``.

.. data:: BIND

   The IP to which to bind the HTTP server. The default is ``"127.0.0.1"``.

.. _url-settings:

URL settings
============

The first thing to understand is that there are currently two supported methods
for URL formation: *relative* and *absolute*. Relative URLs are useful when
testing locally, and absolute URLs are reliable and most useful when
publishing. One method of supporting both is to have one Pelican configuration
file for local development and another for publishing. To see an example of
this type of setup, use the ``pelican-quickstart`` script as described in the
:doc:`Installation <install>` section, which will produce two separate
configuration files for local development and publishing, respectively.

You can customize the URLs and locations where files will be saved. The
``*_URL`` and ``*_SAVE_AS`` variables use Python's format strings. These
variables allow you to place your articles in a location such as
``{slug}/index.html`` and link to them as ``{slug}`` for clean URLs (see
example below). These settings give you the flexibility to place your articles
and pages anywhere you want.

.. note::
    If a ``*_SAVE_AS`` setting contains a parent directory that doesn't match
    the parent directory inside the corresponding ``*_URL`` setting, this may
    cause Pelican to generate unexpected URLs in a few cases, such as when
    using the ``{attach}`` syntax.

If you don't want that flexibility and instead prefer that your generated
output paths mirror your source content's filesystem path hierarchy, try the
following settings::

    PATH_METADATA = r"(?P<path_no_ext>.*)\..*"
    ARTICLE_URL = ARTICLE_SAVE_AS = PAGE_URL = PAGE_SAVE_AS = "{path_no_ext}.html"

Otherwise, you can use a variety of file metadata attributes within URL-related
settings:

* slug
* date
* lang
* author
* category

Example usage::

   ARTICLE_URL = "posts/{date:%Y}/{date:%b}/{date:%d}/{slug}/"
   ARTICLE_SAVE_AS = "posts/{date:%Y}/{date:%b}/{date:%d}/{slug}/index.html"
   PAGE_URL = "pages/{slug}/"
   PAGE_SAVE_AS = "pages/{slug}/index.html"

This would save your articles into something like
``/posts/2011/Aug/07/sample-post/index.html``, save your pages into
``/pages/about/index.html``, and render them available at URLs of
``/posts/2011/Aug/07/sample-post/`` and ``/pages/about/``, respectively.

.. note::
    If you specify a ``datetime`` directive, it will be substituted using the
    input files' date metadata attribute. If the date is not specified for a
    particular file, Pelican will rely on the file's ``mtime`` timestamp. Check
    the `Python datetime documentation`_ for more information.

.. _Python datetime documentation:
    https://docs.python.org/3/library/datetime.html#strftime-and-strptime-behavior

.. data:: RELATIVE_URLS

   Defines whether Pelican should use document-relative URLs or not. Only set
   this to ``True`` when developing/testing and only if you fully understand
   the effect it can have on links/feeds. The default is ``False``.

.. data:: ARTICLE_URL

   The URL to refer to an article. The default is ``"{slug}.html"``.

.. data:: ARTICLE_SAVE_AS

   The place where we will save an article. The default is ``"{slug}.html"``.

.. data:: ARTICLE_LANG_URL

   The URL to refer to an article which doesn't use the default language.
   The default is ``"{slug}-{lang}.html"``.

.. data:: ARTICLE_LANG_SAVE_AS

   The place where we will save an article which doesn't use the default
   language. The default is ``"{slug}-{lang}.html"``.

.. data:: DRAFT_URL

   The URL to refer to an article draft. The default is
   ``"drafts/{slug}.html"``.

.. data:: DRAFT_SAVE_AS

   The place where we will save an article draft. The default is ``"drafts/{slug}.html"``.

.. data:: DRAFT_LANG_URL

   The URL to refer to an article draft which doesn't use the default language.
   The default is ``"drafts/{slug}-{lang}.html"``.

.. data:: DRAFT_LANG_SAVE_AS

   The place where we will save an article draft which doesn't use the default
   language. The default is ``"drafts/{slug}-{lang}.html"``.

.. data:: PAGE_URL

   The URL we will use to link to a page. The default is
   ``"pages/{slug}.html"``.

.. data:: PAGE_SAVE_AS

   The location we will save the page. This value has to be the same as
   PAGE_URL or you need to use a rewrite in your server config. The default
   is ``"pages/{slug}.html"``.

.. data:: PAGE_LANG_URL

   The URL we will use to link to a page which doesn't use the default
   language. The default is ``"pages/{slug}-{lang}.html"``.

.. data:: PAGE_LANG_SAVE_AS

   The location we will save the page which doesn't use the default language.
   The default is ``"pages/{slug}-{lang}.html"``.

.. data:: DRAFT_PAGE_URL

   The URL used to link to a page draft. The default is
   ``"drafts/pages/{slug}.html"``.

.. data:: DRAFT_PAGE_SAVE_AS

   The actual location a page draft is saved at. The default is
   ``"drafts/pages/{slug}.html"``.

.. data:: DRAFT_PAGE_LANG_URL

   The URL used to link to a page draft which doesn't use the default
   language. The default is ``"drafts/pages/{slug}-{lang}.html"``.

.. data:: DRAFT_PAGE_LANG_SAVE_AS

   The actual location a page draft which doesn't use the default language is
   saved at. The default is ``"drafts/pages/{slug}-{lang}.html"``.

.. data:: AUTHOR_URL

   The URL to use for an author. The default is ``"author/{slug}.html"``.

.. data:: AUTHOR_SAVE_AS

   The location to save an author. The default is ``"author/{slug}.html"``.

.. data:: CATEGORY_URL

   The URL to use for a category. The default is ``"category/{slug}.html"``.

.. data:: CATEGORY_SAVE_AS

   The location to save a category. The default is ``"category/{slug}.html"``.

.. data:: TAG_URL

   The URL to use for a tag. The default is ``"tag/{slug}.html"``.

.. data:: TAG_SAVE_AS

   The location to save the tag page. The default is ``"tag/{slug}.html"``.

.. note::

    If you do not want one or more of the default pages to be created (e.g.,
    you are the only author on your site and thus do not need an Authors page),
    set the corresponding ``*_SAVE_AS`` setting to ``""`` to prevent the
    relevant page from being generated.

Pelican can optionally create per-year, per-month, and per-day archives of your
posts. These secondary archives are disabled by default but are automatically
enabled if you supply format strings for their respective ``_SAVE_AS``
settings. Period archives fit intuitively with the hierarchical model of web
URLs and can make it easier for readers to navigate through the posts you've
written over time.

Example usage::

   YEAR_ARCHIVE_SAVE_AS = "posts/{date:%Y}/index.html"
   YEAR_ARCHIVE_URL = "posts/{date:%Y}/"
   MONTH_ARCHIVE_SAVE_AS = "posts/{date:%Y}/{date:%b}/index.html"
   MONTH_ARCHIVE_URL = "posts/{date:%Y}/{date:%b}/"

With these settings, Pelican will create an archive of all your posts for the
year at (for instance) ``posts/2011/index.html`` and an archive of all your
posts for the month at ``posts/2011/Aug/index.html``. These can be accessed
through the URLs ``posts/2011/`` and ``posts/2011/Aug/``, respectively.

.. note::
    Period archives work best when the final path segment is ``index.html``.
    This way a reader can remove a portion of your URL and automatically arrive
    at an appropriate archive of posts, without having to specify a page name.

.. data:: YEAR_ARCHIVE_SAVE_AS

   The location to save per-year archives of your posts. The default is ``""``,
   i.e. this is disabled by default.

.. data:: YEAR_ARCHIVE_URL

   The URL to use for per-year archives of your posts. You should set this if
   you enable per-year archives. The default is ``""``, i.e. this is disabled
   by default.

.. data:: MONTH_ARCHIVE_SAVE_AS

   The location to save per-month archives of your posts. The default is
   ``""``, i.e. this is disabled by default.

.. data:: MONTH_ARCHIVE_URL

   The URL to use for per-month archives of your posts. You should set this if
   you enable per-month archives. The default is ``""``, i.e. this is disabled
   by default.

.. data:: DAY_ARCHIVE_SAVE_AS

   The location to save per-day archives of your posts. The default is ``""``,
   i.e. this is disabled by default.

.. data:: DAY_ARCHIVE_URL

   The URL to use for per-day archives of your posts. You should set this if
   you enable per-day archives. The default is ``""``, i.e. this is disabled by
   default.

``DIRECT_TEMPLATES`` work a bit differently than noted above. Only the
``_SAVE_AS`` settings are available, but it is available for any direct
template.

.. data:: ARCHIVES_SAVE_AS

   The location to save the article archives page. The default is ``"archives.html"``.

.. data:: AUTHORS_SAVE_AS

   The location to save the author list. The default is ``"authors.html"``.

.. data:: CATEGORIES_SAVE_AS

   The location to save the category list. The default is ``"categories.html"``.

.. data:: TAGS_SAVE_AS

   The location to save the tag list. The default is ``"tags.html"``.

.. data:: INDEX_SAVE_AS

   The location to save the list of all articles. The default is ``"index.html"``.

URLs for direct template pages are theme-dependent. Some themes use
corresponding ``*_URL`` setting as string, while others hard-code them:
``"archives.html"``, ``"authors.html"``, ``"categories.html"``,
``"tags.html"``.

.. data:: SLUGIFY_SOURCE

   Specifies from where you want the slug to be automatically generated. Can be
   set to ``title`` to use the "Title:" metadata tag or ``basename`` to use the
   article's file name when creating the slug. The default is ``"title"``.

.. data:: SLUGIFY_USE_UNICODE

   Allow Unicode characters in slugs. Set ``True`` to keep Unicode characters
   in auto-generated slugs. Otherwise, Unicode characters will be replaced
   with ASCII equivalents. The default is ``False``.

.. data:: SLUGIFY_PRESERVE_CASE

   Preserve uppercase characters in slugs. Set ``True`` to keep uppercase
   characters from ``SLUGIFY_SOURCE`` as-is. The default is ``False``.

.. data:: SLUG_REGEX_SUBSTITUTIONS

   Regex substitutions to make when generating slugs of articles and pages.
   Specified as a list of pairs of ``(from, to)`` which are applied in order,
   ignoring case. The default substitutions have the effect of removing
   non-alphanumeric characters and converting internal whitespace to dashes.
   Apart from these substitutions, slugs are always converted to lowercase
   ascii characters and leading and trailing whitespace is stripped. Useful for
   backward compatibility with existing URLs. The default is::

       [
           (r"[^\w\s-]", ""),   # remove non-alphabetical/whitespace/"-" chars
           (r"(?u)\A\s*", ""),  # strip leading whitespace
           (r"(?u)\s*\Z", ""),  # strip trailing whitespace
           (r"[-\s]+", "-"),    # reduce multiple whitespace or "-" to single "-"
       ]

.. data:: AUTHOR_REGEX_SUBSTITUTIONS

   Regex substitutions for author slugs. The default is
   ``SLUG_REGEX_SUBSTITUTIONS``.

.. data:: CATEGORY_REGEX_SUBSTITUTIONS

   Regex substitutions for category slugs. The default is
   ``SLUG_REGEX_SUBSTITUTIONS``.

.. data:: TAG_REGEX_SUBSTITUTIONS

   Regex substitutions for tag slugs. The default is
   ``SLUG_REGEX_SUBSTITUTIONS``.

Time and Date
=============

.. data:: TIMEZONE

   The timezone used in the date information, to generate Atom and RSS feeds.

   If no timezone is defined, UTC is assumed. This means that the generated
   Atom and RSS feeds will contain incorrect date information if your locale is
   not UTC.

   Pelican issues a warning in case this setting is not defined, as it was not
   mandatory in previous versions.

   Have a look at `the wikipedia page`_ to get a list of valid timezone values.

.. _the wikipedia page: https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

.. data:: DEFAULT_DATE

   The default date you want to use.  If ``"fs"``, Pelican will use the file
   system timestamp information (mtime) if it can't get date information from
   the metadata.  If given any other string, it will be parsed by the same
   method as article metadata.  If set to a tuple object, the default datetime
   object will instead be generated by passing the tuple to the
   ``datetime.datetime`` constructor. The default is ``None``.

.. data:: DEFAULT_DATE_FORMAT

   The default date format you want to use. The default is ``"%a %d %B %Y"``,
   e.g. "Mon 06 April 2026".

.. data:: DATE_FORMATS

   If you manage multiple languages, you can set the date formatting here.

   If no ``DATE_FORMATS`` are set, Pelican will fall back to
   ``DEFAULT_DATE_FORMAT``. If you need to maintain multiple languages with
   different date formats, you can set the ``DATE_FORMATS`` dictionary using
   the language name (``lang`` metadata in your post content) as the key.

   In addition to the standard C89 strftime format codes that are listed in
   `Python datetime documentation`_, you can use the ``-`` character between
   ``%`` and the format character to remove any leading zeros. For example,
   ``%d/%m/%Y`` will output ``01/01/2014`` whereas ``%-d/%-m/%Y`` will result
   in ``1/1/2014``.

   .. parsed-literal::

       DATE_FORMATS = {
           "en": "%a, %d %b %Y",
           "jp": "%Y-%m-%d(%a)",
       }

   It is also possible to set different locale settings for each language by
   using a ``(locale, format)`` tuple as a dictionary value which will override
   the ``LOCALE`` setting:

   .. parsed-literal::

      # On Unix/Linux
      DATE_FORMATS = {
          "en": ("en_US", "%a, %d %b %Y"),
          "jp": ("ja_JP", "%Y-%m-%d(%a)"),
      }

      # On Windows
      DATE_FORMATS = {
          "en": ("usa", "%a, %d %b %Y"),
          "jp": ("jpn", "%Y-%m-%d(%a)"),
      }

   The default is ``{}``.

.. data:: LOCALE

   Change the locale. A list of locales can be provided here or a single
   string representing one locale.  When providing a list, all the locales will
   be tried until one works.

   You can set locale to further control date format:

   .. parsed-literal::

      LOCALE = [
          "usa", "jpn",      # On Windows
          "en_US", "ja_JP"   # On Unix/Linux
      ]

   For a list of available locales refer to `locales on Windows`_  or on
   Unix/Linux, use the ``locale -a`` command; see manpage
   `locale(1)`_ for more information. The default is the system locale.


.. _Jinja custom filters documentation: https://jinja.palletsprojects.com/en/latest/api/#custom-filters
.. _Jinja global namespace documentation: https://jinja.palletsprojects.com/en/latest/api/#the-global-namespace
.. _Jinja custom tests documentation: https://jinja.palletsprojects.com/en/latest/api/#custom-tests

.. _locales on Windows: https://www.microsoft.com/en-us/download/details.aspx?id=55979

.. _locale(1): https://linux.die.net/man/1/locale


.. _template_pages:

Template pages
==============

.. data:: TEMPLATE_PAGES

   A mapping containing template pages that will be rendered with the blog
   entries.

   If you want to generate custom pages besides your blog entries, you can
   point any Jinja2 template file with a path pointing to the file and the
   destination path for the generated file.

   For instance, if you have a blog with three static pages — a list of books,
   your resume, and a contact page — you could have::

       TEMPLATE_PAGES = {
           "src/books.html": "dest/books.html",
           "src/resume.html": "dest/resume.html",
           "src/contact.html": "dest/contact.html",
       }

   The default is ``{}``.

.. data:: TEMPLATE_EXTENSIONS

   The extensions to use when looking up template files from template names.
   The default is ``[".html"]``.

.. data:: DIRECT_TEMPLATES

   List of templates that are used directly to render content. Typically direct
   templates are used to generate index pages for collections of content (e.g.,
   category and tag index pages). If the author, category and tag collections are not
   needed, set ``DIRECT_TEMPLATES = ["index", "archives"]``

   ``DIRECT_TEMPLATES`` are searched for over paths maintained in
   ``THEME_TEMPLATES_OVERRIDES``.

   The default is ``["index", "tags", "categories", "authors", "archives"]``.

Metadata
========

.. data:: AUTHOR

   Default author (usually your name). The default is ``None``, which removes the byline.

.. data:: DEFAULT_METADATA

   The default metadata you want to use for all articles and pages. The default
   is ``{}``.

.. data:: FILENAME_METADATA

   The regexp that will be used to extract any metadata from the filename. All
   named groups that are matched will be set in the metadata object.  The
   default value is ``r"(?P<date>\d{4}-\d{2}-\d{2}).*"`` and will only extract
   the date from the filename.

   For example, if your source file were titled ``2026-04-30_blog-article.md``,
   you could extract both the date and the slug::

      FILENAME_METADATA = r"(?P<date>\d{4}-\d{2}-\d{2})_(?P<slug>.*)"

   giving you a date of *April 30, 2026* and a slug of *blog-article*.

   See also ``SLUGIFY_SOURCE``. The default is
   ``r"(?P<date>\d{4}-\d{2}-\d{2}).*"``, i.e. it assumed your filenames start
   with an ISO-style date, e.g. ``2026-04-30``.

   See also, ``FILENAME_METADATA``.

.. data:: PATH_METADATA

   Like ``FILENAME_METADATA``, but parsed from a page's full path relative to
   the content source directory, include the source filename. The default
   value is ``""``.

   For example, if your source files were stored in folders by year and then my
   month, with the filename being the day of the month, (e.g.
   ``2026/04/30.rst``) you could extract that with::

      PATH_METADATA = r"(?P<date>\d{4}/\d{2}/\d{2}).*"

   (The above works on Windows as well.)

   See also ``FILENAME_METADATA``.

.. data:: EXTRA_PATH_METADATA

   Extra metadata dictionaries keyed by relative path. Relative paths require
   correct OS-specific directory separators (i.e. / in UNIX and \\ in Windows)
   unlike some other Pelican file settings. Paths to a directory apply to all
   files under it. The most-specific path wins conflicts.

   Not all metadata needs to be :ref:`embedded in source file itself
   <internal_metadata>`. For example, blog posts are often named following a
   ``YYYY-MM-DD-SLUG.rst`` pattern, or nested into ``YYYY/MM/DD-SLUG``
   directories. To extract metadata from the filename or path, set
   ``FILENAME_METADATA`` or ``PATH_METADATA`` to regular expressions that use
   Python's `group name notation`_ ``(?P<name>…)``. If you want to attach
   additional metadata but don't want to encode it in the path, you can set
   ``EXTRA_PATH_METADATA``:

   .. parsed-literal::

       EXTRA_PATH_METADATA = {
           "relative/path/to/file-1": {
               "key-1a": "value-1a",
               "key-1b": "value-1b",
           },
           "relative/path/to/file-2": {
               "key-2": "value-2",
           },
       }

   This can be a convenient way to shift the output location of a particular
   file:

   .. parsed-literal::

       # Take advantage of the following defaults:
       # STATIC_SAVE_AS = "{path}"
       # STATIC_URL = "{path}"
       STATIC_PATHS = [
           "static/robots.txt",
       ]
       EXTRA_PATH_METADATA = {
           "static/robots.txt": {"path": "robots.txt"},
       }

   .. _group name notation:
      https://docs.python.org/3/library/re.html#regular-expression-syntax

   The default is ``{}``.


Feed settings
=============

By default, Pelican uses Atom feeds. However, it is also possible to use RSS
feeds if you prefer.

Pelican generates category feeds as well as feeds for all your articles. It
does not generate feeds for tags by default, but it is possible to do so using
the ``TAG_FEED_ATOM`` and ``TAG_FEED_RSS`` settings:

.. data:: FEED_DOMAIN

   The domain prepended to feed URLs. Since feed URLs should always be
   absolute, it is highly recommended to define this (e.g.,
   "https://feeds.example.com"). The default is ``SITEURL``.

.. data:: FEED_ATOM

   The location to save the Atom feed. The default is ``None``, for no Atom
   feed.

.. data:: FEED_ATOM_URL

   Relative URL of the Atom feed. If not set, ``FEED_ATOM`` is used both for
   save location and URL. The default is ``None``.

.. data:: FEED_RSS

   The location to save the RSS feed. The default is ``None``, for no RSS feed.

.. data:: FEED_RSS_URL

   Relative URL of the RSS feed. If not set, ``FEED_RSS`` is used both for save
   location and URL. The default is ``None``.

.. data:: FEED_ALL_ATOM

   The location to save the all-posts Atom feed: this feed will contain all
   posts regardless of their language. The default is ``"feeds/all.atom.xml"``.

.. data:: FEED_ALL_ATOM_URL

   Relative URL of the all-posts Atom feed. If not set, ``FEED_ALL_ATOM`` is
   used both for save location and URL. The default is ``None``.

.. data:: FEED_ALL_RSS

   The location to save the the all-posts RSS feed: this feed will contain all
   posts regardless of their language. The default is ``None``, for no
   all-posts RSS feed.

.. data:: FEED_ALL_RSS_URL

   Relative URL of the all-posts RSS feed. If not set, ``FEED_ALL_RSS`` is used
   both for save location and URL. The default is ``None``.

.. data:: CATEGORY_FEED_ATOM

   The location to save the category Atom feeds. [2]_ The default is
   ``"feeds/{slug}.atom.xml"``.

.. data:: CATEGORY_FEED_ATOM_URL

   Relative URL of the category Atom feeds, including the ``{slug}``
   placeholder. [2]_ If not set, ``CATEGORY_FEED_ATOM`` is used both for save
   location and URL. The default is ``None``.

.. data:: CATEGORY_FEED_RSS

   The location to save the category RSS feeds, including the ``{slug}``
   placeholder. [2]_ The default is ``None``, for no RSS feed.

.. data:: CATEGORY_FEED_RSS_URL

   Relative URL of the category RSS feeds, including the ``{slug}``
   placeholder. [2]_ If not set, ``CATEGORY_FEED_RSS`` is used both for save
   location and URL. The default is ``None``.

.. data:: AUTHOR_FEED_ATOM

   The location to save the author Atom feeds. [2]_ The default is
   ``"feeds/{slug}.atom.xml"``.

.. data:: AUTHOR_FEED_ATOM_URL

   Relative URL of the author Atom feeds, including the ``{slug}`` placeholder.
   [2]_ If not set, ``AUTHOR_FEED_ATOM`` is used both for save location and
   URL. The default is ``None`` (not set).

.. data:: AUTHOR_FEED_RSS

   The location to save the author RSS feeds. [2]_ The default is
   ``"feeds/{slug}.rss.xml"``.

.. data:: AUTHOR_FEED_RSS_URL

   Relative URL of the author RSS feeds, including the ``{slug}`` placeholder.
   [2]_ If not set, ``AUTHOR_FEED_RSS`` is used both for save location and URL.
   The default is ``None``.

.. data:: TAG_FEED_ATOM

   The location to save the tag Atom feed, including the ``{slug}``
   placeholder. [2]_ The default is ``None``, for no tag feed.

.. data:: TAG_FEED_ATOM_URL

   Relative URL of the tag Atom feed, including the ``{slug}`` placeholder.
   [2]_ The default is ``None``.

.. data:: TAG_FEED_RSS

   Relative URL to output the tag RSS feed, including the ``{slug}``
   placeholder. If not set, ``TAG_FEED_RSS`` is used both for save location and
   URL. The default is ``None``, for no tag feed.

.. data:: FEED_MAX_ITEMS

   Maximum number of items allowed in a feed. Setting to ``None`` will cause the
   feed to contains every article. The default is ``100``.

.. data:: RSS_FEED_SUMMARY_ONLY

   Only include item summaries in the ``description`` tag of RSS feeds. If set
   to ``False``, the full content will be included instead. This setting
   doesn't affect Atom feeds, only RSS ones. The default is ``True``.

.. data:: FEED_APPEND_REF

   If set to ``True``, ``?ref=feed`` will be appended to links in generated
   feeds for the purpose of referrer tracking. The default is ``False``.

If you don't want to generate some or any of these feeds, set the above
variables to ``None``.

.. [2] ``{slug}`` is replaced by name of the category / author / tag.


Pagination
==========

The default behaviour of Pelican is to list all the article titles along with a
short description on the index page. While this works well for small-to-medium
sites, sites with a large quantity of articles will probably benefit from
paginating this list.

You can use the following settings to configure the pagination.

.. data:: DEFAULT_ORPHANS

   The minimum number of articles allowed on the last page. Use this when you
   don't want the last page to only contain a handful of articles. The default
   is ``0``.

.. data:: DEFAULT_PAGINATION

   The maximum number of articles to include on a page, not including orphans.
   False to disable pagination. The default is ``False``.

.. data:: PAGINATED_TEMPLATES

   The templates to use pagination with, and the number of articles to include
   on a page. If this value is ``None``, it defaults to ``DEFAULT_PAGINATION``.
   The default is ``{"index": None, "tag": None, "category": None, "author": None}``.

.. data:: PAGINATION_PATTERNS

   A set of patterns that are used to determine advanced pagination output. The
   default is::

       (
           (1, "{name}{extension}", "{name}{extension}"),
           (2, "{name}{number}{extension}", "{name}{number}{extension}""),
       )


Using Pagination Patterns
-------------------------

By default, pages subsequent to ``.../foo.html`` are created as
``.../foo2.html``, etc. The ``PAGINATION_PATTERNS`` setting can be used to
change this. It takes a sequence of triples, where each triple consists of::

    (minimum_page, page_url, page_save_as,)

For ``page_url`` and ``page_save_as``, you may use a number of variables.
``{url}`` and ``{save_as}`` correspond respectively to the ``*_URL`` and
``*_SAVE_AS`` values of the corresponding page type (e.g. ``ARTICLE_SAVE_AS``).
If ``{save_as} == foo/bar.html``, then ``{name} == foo/bar`` and ``{extension}
== .html``. ``{base_name}`` equals ``{name}`` except that it strips trailing
``/index`` if present. ``{number}`` equals the page number.

For example, if you want to leave the first page unchanged, but place
subsequent pages at ``.../page/2/`` etc, you could set ``PAGINATION_PATTERNS``
as follows::

  PAGINATION_PATTERNS = (
      (1, "{url}", "{save_as}"),
      (2, "{base_name}/page/{number}/", "{base_name}/page/{number}/index.html"),
  )


If you want a pattern to apply to the last page in the list, use ``-1``
as the ``minimum_page`` value::

    (-1, "{base_name}/last/", "{base_name}/last/index.html"),

Translations
============

Pelican offers a way to translate articles. See the :doc:`Content <content>`
section for more information.

.. data:: DEFAULT_LANG

   The default language to use. The default is ``"en"``.

.. data:: ARTICLE_TRANSLATION_ID

   The metadata attribute(s) used to identify which articles are translations
   of one another. May be a string or a collection of strings. Set to ``None``
   or ``False`` to disable the identification of translations. The default is
   ``"slug"``.

.. data:: PAGE_TRANSLATION_ID

   The metadata attribute(s) used to identify which pages are translations of
   one another. May be a string or a collection of strings. Set to ``None`` or
   ``False`` to disable the identification of translations. The default is
   ``"slug"``.

.. data:: TRANSLATION_FEED_ATOM

   The location to save the Atom feed for translations. [3]_ The default is
   ``"feeds/all-{lang}.atom.xml"``.

.. data:: TRANSLATION_FEED_ATOM_URL

   Relative URL of the Atom feed for translations, including the ``{lang}``
   placeholder. [3]_ If not set, ``TRANSLATION_FEED_ATOM`` is used both for
   save location and URL. The default is ``None``.

.. data:: TRANSLATION_FEED_RSS

   Where to put the RSS feed for translations. The default is ``None``,
   meaning no RSS feed.

.. data:: TRANSLATION_FEED_RSS_URL

   Relative URL of the RSS feed for translations, including the ``{lang}``
   placeholder. [3]_ If not set, ``TRANSLATION_FEED_RSS`` is used both for save
   location and URL. The default is ``None``.

.. [3] {lang} is the language code

Ordering content
================

.. data:: NEWEST_FIRST_ARCHIVES

   Order archives by newest first by date. (False: orders by date with older
   articles first.) The default is ``True``.

.. data:: REVERSE_CATEGORY_ORDER

   Reverse the category order. (True: lists by reverse alphabetical order;
   default lists alphabetically.) The default is ``False``.

.. data:: ARTICLE_ORDER_BY

   Defines how the articles (``articles_page.object_list`` in the template) are
   sorted. Valid options are: metadata as a string (use ``reversed-`` prefix
   to reverse the sort order), special option ``"basename"`` which will use
   the basename of the file (without path), or a custom function to extract the
   sorting key from articles. Using a value of ``"date"`` will sort articles in
   chronological order, while the default value, ``"reversed-date"``, will sort
   articles by date in reverse order (i.e., newest article comes first). The
   default is ``"reversed-date"``.

.. data:: PAGE_ORDER_BY

   Defines how the pages (``pages`` variable in the template) are sorted.
   Options are same as ``ARTICLE_ORDER_BY``.  The default value, ``"basename"``
   will sort pages by their basename. The default is ``"basename"``.


.. _settings/themes:

Themes
======

Creating Pelican themes is addressed in a dedicated section (see
:ref:`theming-pelican`). However, here are the settings that are related to
themes.

.. data:: THEME

   Theme to use to produce the output. Can be a relative or absolute path to a
   theme folder, or the name of a default theme or a theme installed via
   :doc:`pelican-themes` (see below). The default theme is "notmyidea".

.. data:: THEME_STATIC_DIR

   Destination directory in the output path where Pelican will place the files
   collected from `THEME_STATIC_PATHS`. Default is `theme`. The default is
   ``"theme"``.

.. data:: THEME_STATIC_PATHS

   Static theme paths you want to copy. Default value is `static`, but if your
   theme has other static paths, you can put them here. If files or directories
   with the same names are included in the paths defined in this settings, they
   will be progressively overwritten. The default is ``["static"]``.

.. data:: THEME_TEMPLATES_OVERRIDES

   A list of paths you want Jinja2 to search for templates before searching the
   theme's ``templates/`` directory.  Allows for overriding individual theme
   template files without having to fork an existing theme.  Jinja2 searches in
   the following order: files in ``THEME_TEMPLATES_OVERRIDES`` first, then the
   theme's ``templates/``. The default is ``[]``.

   You can also extend templates from the theme using the ``{% extends %}``
   directive utilizing the ``!theme`` prefix as shown in the following example:

   .. parsed-literal::

      {% extends '!theme/article.html' %}

.. data:: CSS_FILE

   Specify the CSS file you want to load. The default is ``"main.css"``.

By default, two themes are available. You can specify them using the ``THEME``
setting or by passing the ``-t`` option to the ``pelican`` command:

* notmyidea
* simple (a synonym for "plain text" :)

There are a number of other themes available at
https://github.com/getpelican/pelican-themes. Pelican comes with
:doc:`pelican-themes`, a small script for managing themes.

You can define your own theme, either by starting from scratch or by
duplicating and modifying a pre-existing theme. Here is :doc:`a guide on how to
create your theme <themes>`.

Following are example ways to specify your preferred theme::

    # Specify name of a built-in theme
    THEME = "notmyidea"
    # Specify name of a theme installed via the pelican-themes tool
    THEME = "chunk"
    # Specify a customized theme, via path relative to the settings file
    THEME = "themes/mycustomtheme"
    # Specify a customized theme, via absolute path
    THEME = "/home/myuser/projects/mysite/themes/mycustomtheme"

Simple Theme
------------

The built-in ``simple`` theme can be customized using the following settings:

.. data:: STYLESHEET_URL

   The URL of the stylesheet to use. The default is ``None``.

The built-in ``notmyidea`` theme can make good use of the following settings.
Feel free to use them in your themes as well.

.. data:: SITESUBTITLE

   A subtitle to appear in the header. The default is ``None``.

.. data:: DISQUS_SITENAME

   Pelican can handle Disqus comments. Specify the Disqus sitename identifier
   here. The default is ``None``.

.. data:: GITHUB_URL

   Your GitHub URL (if you have one). It will then use this information to
   create a GitHub ribbon. The default is ``None``.

.. data:: ANALYTICS

   Put any desired analytics scripts in this setting in ``publishconf.py``.
   Example:

   .. parsed-literal::

      ANALYTICS = """
          <script src="/theme/js/primary-analytics.js"></script>
          <script>
              [ … in-line Javascript code for secondary analytics … ]
          </script>
      """

   The default is ``None``.

.. data:: MENUITEMS

   A list of tuples (Title, URL) for additional menu items to appear at the
   beginning of the main menu. The default is ``None``.

.. data:: LINKS

   A list of tuples (Title, URL) for links to appear on the header. The
   default is ``None``.

.. data:: SOCIAL

   A list of tuples (Title, URL) to appear in the "social" section. The
   default is ``None``.

.. data:: TWITTER_USERNAME

   Allows for adding a button to articles to encourage others to tweet about
   them. Add your Twitter username if you want this button to appear. The
   default is ``None``.

.. data:: LINKS_WIDGET_NAME

   Allows override of the name of the links widget.  If not specified, defaults
   to "links". The default is ``None``.

.. data:: SOCIAL_WIDGET_NAME

   Allows override of the name of the "social" widget.  If not specified,
   defaults to "social". The default is ``None``.

Notmyidea Theme
---------------

In addition, you can use the "wide" version of the ``notmyidea`` theme by
adding the following to your configuration::

    CSS_FILE = "wide.css"


Logging
=======

Sometimes, a long list of warnings may appear during site generation. Finding
the **meaningful** error message in the middle of tons of annoying log output
can be quite tricky. In order to filter out redundant log messages, Pelican
comes with the ``LOG_FILTER`` setting.

``LOG_FILTER`` should be a list of tuples ``(level, msg)``, each of them being
composed of the logging level (up to ``warning``) and the message to be
ignored. Simply populate the list with the log messages you want to hide, and
they will be filtered out.

For example::

   import logging
   LOG_FILTER = [(logging.WARN, "TAG_SAVE_AS is set to False")]

It is possible to filter out messages by a template. Check out source code to
obtain a template.

For example::

   import logging
   LOG_FILTER = [(logging.WARN, "Empty alt attribute for image %s in %s")]

.. Warning::

   Silencing messages by templates is a dangerous feature. It is possible to
   unintentionally filter out multiple message types with the same template
   (including messages from future Pelican versions). Proceed with caution.

.. note::

    This option does nothing if ``--debug`` is passed.

.. _reading_only_modified_content:


Reading Only Modified Content
=============================

To speed up the build process, Pelican can optionally read only articles and
pages with modified content.

When Pelican is about to read some content source file:

1. The hash or modification time information for the file from a
   previous build are loaded from a cache file if ``LOAD_CONTENT_CACHE`` is
   ``True``. These files are stored in the ``CACHE_PATH`` directory.  If the
   file has no record in the cache file, it is read as usual.
2. The file is checked according to ``CHECK_MODIFIED_METHOD``:

   - If set to ``"mtime"``, the modification time of the file is
     checked.
   - If set to a name of a function provided by the ``hashlib``
     module, e.g. ``"md5"``, the file hash is checked.
   - If set to anything else or the necessary information about the
     file cannot be found in the cache file, the content is read as usual.

3. If the file is considered unchanged, the content data saved in a
   previous build corresponding to the file is loaded from the cache, and the
   file is not read.
4. If the file is considered changed, the file is read and the new
   modification information and the content data are saved to the cache if
   ``CACHE_CONTENT`` is ``True``.

If ``CONTENT_CACHING_LAYER`` is set to ``"reader"`` (the default), the raw
content and metadata returned by a reader are cached. If this setting is
instead set to ``"generator"``, the processed content object is cached. Caching
the processed content object may conflict with plugins (as some reading related
signals may be skipped) and the ``WITH_FUTURE_DATES`` functionality (as the
``draft`` status of the cached content objects would not change automatically
over time).

Checking modification times is faster than comparing file hashes, but it is not
as reliable because ``mtime`` information can be lost, e.g., when copying
content source files using the ``cp`` or ``rsync`` commands without the
``mtime`` preservation mode (which for ``rsync`` can be invoked by passing the
``--archive`` flag).

The cache files are Python pickles, so they may not be readable by different
versions of Python as the pickle format often changes. If such an error is
encountered, it is caught and the cache file is rebuilt automatically in the
new format. The cache files will also be rebuilt after the ``GZIP_CACHE``
setting has been changed.

The ``--ignore-cache`` command-line option is useful when the whole cache needs
to be regenerated, such as when making modifications to the settings file that
will affect the cached content, or just for debugging purposes. When Pelican
runs in autoreload mode, modification of the settings file will make it ignore
the cache automatically if ``AUTORELOAD_IGNORE_CACHE`` is ``True``.

Note that even when using cached content, all output is always written, so the
modification times of the generated ``*.html`` files will always change.
Therefore, ``rsync``-based uploading may benefit from the ``--checksum``
option.


Example settings
================

.. literalinclude:: ../samples/pelican.conf.py
    :language: python


.. _Jinja Environment documentation: https://jinja.palletsprojects.com/en/latest/api/#jinja2.Environment
.. _Docutils Configuration: http://docutils.sourceforge.net/docs/user/config.html
.. _`watchfiles documentation`: https://watchfiles.helpmanual.io/api/filters/#watchfiles.DefaultFilter.ignore_dirs
