Metadata-Version: 2.1
Name: wikitextprocessor
Version: 0.4.95
Summary: Parser and expander for Wikipedia, Wiktionary etc. dump files, with Lua execution support
Home-page: https://github.com/tatuylonen/wikitextprocessor
Author: Tatu Ylonen
Author-email: ylo@clausal.com
License: MIT (some included files have other free licences)
Download-URL: https://github.com/tatuylonen/wikitextprocessor
Keywords: dictionary,wiktionary,wikipedia,data extraction,wikitext,scribunto,lua
Platform: UNKNOWN
Classifier: Development Status :: 3 - Alpha
Classifier: Intended Audience :: Developers
Classifier: Intended Audience :: Science/Research
Classifier: License :: OSI Approved :: MIT License
Classifier: Natural Language :: English
Classifier: Operating System :: POSIX :: Linux
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 3 :: Only
Classifier: Topic :: Text Processing
Classifier: Topic :: Text Processing :: Linguistic
Description-Content-Type: text/markdown
License-File: LICENSE

# wikitextprocessor

This is a Python package for processing [WikiMedia dump
files](https://dumps.wikimedia.org) for
[Wiktionary](https://www.wiktionary.org),
[Wikipedia](https://www.wikipedia.org), etc., for data extraction,
error checking, offline conversion into HTML or other formats, and
other uses.  Key features include:

* Parsing dump files, including built-in support for processing pages
  in parallel
* [Wikitext](https://en.wikipedia.org/wiki/Help:Wikitext) syntax
  parser that converts the whole page into a parse tree
* Extracting template definitions and
  [Scribunto](https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual)
  Lua module definitions from dump files
* Expanding selected templates or all templates, and
  heuristically identifying templates that need to be expanded before
  parsing is reasonably possible (e.g., templates that emit table
  start and end tags)
* Processing and expanding wikitext parser functions
* Processing, executing, and expanding Scribunto Lua modules (they are
  very widely used in, e.g., Wiktionary, for example for generating
  [IPA](https://en.wikipedia.org/wiki/International_Phonetic_Alphabet)
  strings for many languages)
* Controlled expansion of parts of pages for applications that parse
  overall page structure before parsing but then expand templates on
  certain sections of the page
* Capturing information from template arguments while expanding them,
  as template arguments often contain useful information not available
  in the expanded content.

This module is primarily intended as a building block for other
packages that process Wikitionary or Wikipedia data, particularly for
data extraction.  You will need to write code to use this.

For pre-existing extraction modules that use this package, please see:

* [Wiktextract](https://github.com/tatuylonen/wiktextract/) for
  extracting rich machine-readable dictionaries from Wiktionary.  You can also
  find pre-extracted machine-readable Wiktionary data in JSON format at
  [kaikki.org](https://kaikki.org/dictionary).

## Getting started

### Installing

The best way to install this package is from [pypi](https://pypi.org):
```
pip3 install wikitextprocessor
```

Alternatively, you can install the master branch from github:
```
git clone https://github.com/tatuylonen/wikitextprocessor
cd wikitextprocessor
pip3 install -e .
```

### Running tests

This package includes tests written using the ``unittest`` framework.
They can be run using, for example, ``nose``, which can be installed
using ``pip3 install nose``.

To run the tests, use the following command in the top-level directory:
```
nosetests
```

### Obtaining WikiMedia dump files

This package is primarily intended for processing Wiktionary and
Wikipedia dump files (though you can also use it for processing
individual pages or other files that are in wikitext format).  To
download WikiMedia dump files, go to the [dump download
page](https://dumps.wikimedia.org/backup-index.html).  We recommend
using the &lt;name&gt;-&lt;date&gt;-pages-articles.xml.bz2 files.

## API documentation

Usage example:

```
   from wikitextprocessor import Wtp, WikiNode, NodeKind
   ctx = Wtp()

   def page_handler(model, title, text):
       if model != "wikitext" or title.startswith("Template:"):
           return None
       tree = ctx.parse(text, pre_expand=True)
       ... process parse tree
         ... value = ctx.node_to_wikitext(node)

   ctx.process("enwiktionary-20201201-pages-articles.xml.bz2", page_handler)
```

The basic operation of ``Wtp.process()`` is as follows:
* Extract templates, modules, and other pages from the dump file and save
  them in a temporary file
* Heuristically analyze which templates need to be pre-expanded before
  parsing to make sense of the page structure (this cannot detect templates
  that call Lua code that outputs wikitext that affects parsed structure).
  These first steps together are called the "first phase".
* Process the pages again, calling a page handler function for each page.
  The page handler can extract, parse, and otherwise process the page, and
  has full access to templates and Lua macros defined in the dump.  This may
  call the page handler in multiple processes in parallel.  Return values
  from the page handler calls are returned to the caller (this function acts
  as an iterator).  This is called the second phase.
* Optionally, the ``Wtp.reprocess()`` function may be used for processing the
  same data several times (it basically repeats the second phase).

Most of the functionality is hidden behind the ``Wtp`` object.
``WikiNode`` objects are used for representing the parse
tree that is returned by the ``Wtp.parse()`` function.  ``NodeKind``
is an enumeration type used to encode the type of a ``WikiNode``.
Additionally, ``ALL_LANGUAGES`` is exported and is a list that
describes all languages (language codes, names, and other data) used
in Wiktionary.

### class Wtp(object)

```
def __init__(self, num_threads=None, cache_file=None, quiet=False)
```

The initializer can usually be called without arguments, but recognizes
the following arguments:
* ``num_threads`` - if set to an integer, use that many parallel processes
  for processing the dump.  The default is to use as many processors as there
  are available cores/hyperthreads.  You may need to limit the number of
  parallel processes if you are limited by available memory; we have found
  that processing Wiktionary (including templates and Lua macros)
  requires 3-4GB of memory per process.  This MUST be set to 1 on Windows.
* ``cache_file`` can normally be ``None``, in which case a temporary file will
  be created under ``/tmp``, or a path (str) for the cache file(s).
  There are two reasons why you might want to
  set this: 1) you don't have enough space on ``/tmp`` (the whole uncompressed
  dump must fit there, which can easily be 10-20GB), or 2) for testing.
  If you specify the cache file, if an existing cache file exists, that will be
  loaded and used, eliminating the time needed for Phase 1 (this is very
  important for testing, allowing processing single pages reasonably fast).
  In this case, you should not call ``Wtp.process()`` but instead use
  ``Wtp.reprocess()`` or just call ``Wtp.expand()`` or ``Wtp.parse()`` on
  wikitext that you have obtained otherwise (e.g., from some file).
  If the cache file doesn't exist, you will need to call ``Wtp.process()``
  to parse a dump file, which will initialize the cache file during the
  first phase.  If you wish to re-create cache file, you should remove
  the old cache file first.  The cache file path is actually a prefix for
  multiple individual files.
* ``quiet`` - if set to True, suppress progress messages during processing

**Windows and MacOS note:** Setting ``num_threads`` to a value other than 1
probably doesn't currently work on Windows and MacOS.  It now defaults to 1
on these platforms.  This is because these platforms don't use ``fork()`` in
the Python multiprocessing package, and the current parallelization
implementation depends on this.

```
def process(self, path, page_handler, phase1_only=False)
```

This function processes a WikiMedia dump, uncompressing and extracing pages
(including templates and Lua modules), and calling ``Wtp.add_page()`` for
each page (phase 1).  This then calls ``Wtp.reprocess()`` to execute the
second phase.

This takes the following arguments:
* ``path`` (str) - path to the WikiMedia dump file to be processed
  (e.g., "enwiktionary-20201201-pages-articles.xml.bz2").  Note that the
  compressed file can be used.  Dump files can be
  downloaded [here](https://dumps.wikimedia.org).
* ``page_handler`` (function) - this function will be called for each page
  in phase 2 (unless ``phase1_only`` is set to True).  The call takes the form
  ``page_handler(model, title, data)``, where ``model`` is the ``model`` value
  for the page in the dump (``wikitext`` for normal wikitext pages and
  templates, ``Scribunto`` for Lua modules; other values are also possible),
  ``title`` is page title (e.g., ``sample`` or ``Template:foobar``
  or ``Module:mystic``), and ``data`` is the contents of the page (usually
  wikitext).
* ``phase1_only`` (boolean) - if set to True, prevents phase 2
  processing and the ``page_handler`` function will not be called.  The
  ``Wtp.reprocess()`` function can be used to run the second phase separately,
  or ``Wtp.expand()``, ``Wtp.parse()`` and other functions can be used.

This function returns an iterator over the values returned by the
``page_handler`` function (if ``page_handler`` returns ``None`` or no
value, the iterator does not return those values).  Note that
``page_handler`` will usually be run in a separate process, and cannot
pass any values back in global variables.  It can, however, access
global variables assigned before calling ``Wtp.process()`` (in Linux
only).

```
def reprocess(self, page_handler, autoload=True)
```

Iterates over all pages in the cache file and calls ``page_handler``
for each page.  This basically implements phase 2 of processing a dump
file (see ``Wtp.process()``).  This can be called more than once if desired.

The arguments are:
* ``page_handler`` (function) - this function will be called for every page.
  The call takes the form ``page_handler(model, title, data)``,
  where ``model`` is the ``model`` value
  for the page in the dump (``wikitext`` for normal wikitext pages and
  templates, ``Scribunto`` for Lua modules; other values are also possible),
  ``title`` is page title (e.g., ``sample`` or ``Template:foobar``
  or ``Module:mystic``), and ``data`` is the contents of the page (usually
  wikitext).  If ``autoload`` is set to ``False``, then ``data`` will be
  ``None``.
* ``autoload`` (boolean) - Normally this function loads the page contents
  automatically before calling the page handler.  If ``autoload`` is set to
  ``False``, then this will not automatically load the contents.  This will
  make the iteration over the pages much faster, and is useful for scanning
  all pages when only a small fraction of them are likely to be of interest.
  The ``Wtp.read_by_title()`` function can then be used to load the page
  contents.

This function returns an iterator that iterates over the return values
of ``page_handler``.  If the return value is ``None`` or ``page_handler``
returns no value, no value is returned by the iterator for such calls.

This calls the ``page_handler`` using subprocesses (unless ``num_threads``
was set to 1 in the initializer).  It may be necessary to set it to 1
on Windows and MacOS due to operating system/python limitations on those
platforms.

```
def read_by_title(self, title):
```

Reads the contents of the page with the specified title from the cache
file.  There is usually no need to call this function explicitly, as
``Wtp.process()`` and ``Wtp.reprocess()`` normally load the page
automatically.  However, this can be useful if calling
``Wtp.reprocess()`` with ``autoload`` set to ``False``.  This function
does not automatically call ``Wtp.start_page()``.

Arguments are:
* ``title`` (str) - the title of the page to read

This returns the page contents as a string, or ``None`` if the page
does not exist.  If a transient page has been added with that title
(see ``Wtp.add_page()``), then this returns the transient page.

```
def parse(self, text, pre_expand=False, expand_all=False,
          additional_expand=None)
```

Parses wikitext into a parse tree (``WikiNode``), optionally expanding
some or all the templates and Lua macros in the wikitext (using the definitions
for the templates and macros in the cache files, as added by ``Wtp.process()``
or calls to ``Wtp.add_page()``.

The ``Wtp.start_page()`` function must be called before this function
to set the page title (which may be used by templates, Lua macros, and
error messages).  The ``Wtp.process()`` and ``Wtp.reprocess()``
functions will call it automatically.

This accepts the following arguments:
* ``text`` (str) - the wikitext to be parsed
* ``pre_expand`` (boolean) - if set to ``True``, the templates that were
  heuristically detected as affecting parsing (e.g., expanding to table start
  or end tags or list items) will be automatically expanded before parsing.
  Any Lua macros those templates use may also be called.
* ``expand_all`` - if set to ``True``, expands all templates and Lua
  macros in the wikitext before parsing.
* ``additional_expand`` (set or ``None``) - if this argument is provided, it
  should be a set of template names that should be expanded in addition to
  those specified by the other options (i.e., in addition to to the
  heuristically detected templates if ``pre_expand`` is ``True`` or just these
  if it is false; this option is meaningless if ``expand_all`` is set to
  ``True``).

This returns the parse tree.  See below for a documentation of the ``WikiNode``
class used for representing the parse tree.

```
def node_to_wikitext(self, node)
```

Converts a part of a parse tree back to wikitext.
* ``node`` (``WikiNode``, str, list/tuple of these) - This is the part of the
  parse tree that is to be converted back to wikitext.  We also allow
  strings and lists, so that ``node.children`` can be used directly as
  the argument.


```
def expand(self, text, template_fn=None, post_template_fn=None,
           pre_expand=False, templates_to_expand=None,
           expand_parserfns=True, expand_invoke=True)
```

Expands the selected templates, parser functions and Lua macros in the
given Wikitext.  This can selectively expand some or all templates.  This can
also capture the arguments and/or the expansion of any template as well as
substitute custom expansions instead of the default expansions.

The ``Wtp.start_page()`` function must be called before this function to
set the page title (which may be used by templates and Lua macros).  The
``Wtp.process()`` and ``Wtp.reprocess()`` will call it automatically.  The
page title is also used in error messages.

The arguments are as follows:
* ``text`` (str) - the wikitext to be expanded
* ``template_fn`` (function) - if set, this will be called as
  ``template_fn(name, args)``, where ``name`` (str) is the name of the
  template and ``args`` is a dictionary containing arguments to the
  template.  Positional arguments (and named arguments with numeric
  names) will have integer keys in the dictionary, whereas other named
  arguments will have their names as keys.  All values corresponding
  to arguments are strings (after they have been expanded).  This
  function can return ``None`` to cause the template to be expanded in
  the normal way, or a string that will be used instead of the
  expansion of the template.  This can return ``""`` (empty string) to
  expand the template to nothing.  This can also capture the template name
  and its arguments.
* ``post_template_fn`` (function) - if set, this will be called
  as ``post_template_fn(name, ht, expansion)`` after the template has
  been expanded in the normal way.  This can return ``None`` to use the
  default expansion, or a string to use a that string as the expansion.
  This can also be used to capture the template, its arguments, and/or its
  expansion.
* ``pre_expand`` (boolean) - if set to ``True``, all templates that were
  heuristically determined as needing to be expanded before parsing will be
  expanded.
* ``templates_to_expand`` (``None`` or set or dictionary) - if this is set,
  these templates will be expanded in addition to any other templates that
  have been specified to be expanded.  If a dictionary is provided, its keys
  will be taken as the names of the templates to be expanded.  If this has not
  been set or is ``None``, all templates will be expanded.
* ``expand_parserfns`` (boolean) - Normally, wikitext parser functions will
  be expanded.  This can be set to ``False`` to prevent parser function
  expansion.
* ``expand_invoke`` (boolean) - Normally, the ``#invoke`` parser function
  (which calls a Lua module) will be expanded along with other parser
  functions.  This can be set to ``False`` to prevent expansion of the
  ``#invoke`` parser function.

```
def start_page(self, title)
```

This function should be called before starting the processing of a new page
or file.  This saves the page title (which is frequently accessed by
templates, parser functions, and Lua macros).  The page title is also
used in error messages.

The ``Wtp.process()`` and ``Wtp.reprocess()`` functions will automatically
call this before calling the page handler for each page.  This needs to be
called manually when processing wikitext obtained from other sources.

The arguments are as follows:
* ``title`` (str) - The page title.  For normal pages, there is usually no
  prefix.  Templates typically have ``Template:`` prefix and Lua modules
  ``Module:`` prefix, and other prefixes are also used (e.g., ``Thesaurus:``).
  This does not care about the form of the name, but some parser functions do.

```
def start_section(self, title)
```

Sets the title of the current section on the page.  This is
automatically reset to ``None`` by ``Wtp.start_page()``.  The section
title is only used in error, warning, and debug messages.

The arguments are:
* ``title`` (str) - the title of the section, or ``None`` to clear it.


```
def start_subsection(self, title)
```

Sets the title of the current subsection of the current section on the
page.  This is autimatically reset to ``None`` by ``Wtp.start_page()``
and ``Wtp.start_section()``.  The subsection title is only used in error,
warning, and debug messages.

The arguments are:
* ``title`` (str) - the title of the subsection, or ``None`` to clear it.

```
def add_page(self, model, title, text, transient=False)
```

This function is used to add pages, templates, and modules for
processing.  There is usually no need to use this if ``Wtp.process()``
is used; however, this can be used to add templates and pages for
testing or other special processing needs.  This can also be used for
adding transient pages that are not stored in the cache file but could
be used for debugging or information extraction.  An example would be
overriding some Lua module from the dump file for debugging the Lua
code, or adding a new Lua module that can import other modules and
then dump data from them, for example to extract the category
hierarchy of Wiktionary pages.

The arguments are:
* ``model`` (str) - the model value for the page (usually ``wikitext``
  for normal pages and templates and ``Scribunto`` for Lua modules)
* ``title`` (str) - the title of the page to be added (normal pages typically
  have no prefix in the title, templates begin with ``Template:``, and Lua
  modules begin with ``Module:``)
* ``text`` (str) - the content of the page, template, or module
* ``transient`` (boolean) - normally, the added pages will be stored in
  the cache file.  If this is set to ``True``, the page will not be stored
  in the cache file and will only affect the current run.  Transient
  pages will override any pages in the cache file, and are useful for
  debugging and data extraction.

The ``Wtp.analyze_templates()`` function needs to be called after
calling ``Wtp.add_page()`` before pages can be expanded or parsed (it should
preferably only be called once after adding all pages and templates).

```
def analyze_templates(self)
```

Analyzes the template definitions in the cache file and determines which
of them should be pre-expanded before parsing because they affect the
document structure significantly.  Some templates in, e.g., Wiktionary
expand to table start tags, table end tags, or list items, and parsing
results are generally much better if they are expanded before parsing.
The actual expansion only happens if ``pre_expand`` or some other argument
to ``Wtp.expand()`` or ``Wtp.parse()`` tells them to do so.

The analysis is heuristic and is not guaranteed to find every such template.
In particular, it cannot detect templates that call Lua modules that output
Wikitext control structures (there are several templates in Wiktionary that
call Lua code that outputs list items, for example).  Such templates may need
to be identified manually and specified as additional templates to expand.
Luckily, there seem to be relatively few such templates, at least in
Wiktionary.

This function is automatically called by ``Wtp.process()`` at the end of
phase 1.  An explicit call is only necessary if ``Wtp.add_page()`` has been
used by the application.

### Error handling

Various functions in this module, including ``Wtp.parse()`` and
``Wtp.expand()`` may generate errors and warnings.  Those will be displayed
on ``stdout`` as well as collected in ``Wtp.errors``, ``Wtp.warnings``, and
``Wtp.debugs``.  These fields will contain lists of dictionaries, where
each dictionary describes an error/warning/debug message.  The dictionary can
have the following keys (not all of them are always present):
* ``msg`` (str) - the error message
* ``trace`` (str or ``None``) - optional stacktrace where the error occurred
* ``title`` (str) - the page title on which the error occurred
* ``section`` (str or ``None``) - the section where the error occurred
* ``subsection`` (str or ``None``) - the subsection where the error occurred
* ``path`` (tuple of str) - a path of title, template names, parser function
  names, or Lua module/function names, giving information about where the
  error occurred during expansion or parsing.

The fields containing the error messages will be cleared by every call
to ``Wtp.start_page()`` (including the implicit calls during
``Wtp.process()`` and ``Wtp.reprocess()``).  Thus, the
``page_handler`` function often returns these lists together with any
information extracted from the page, and they can be collected
together from the values returned by the iterators returned by these
functions.  The ``Wtp.to_return()`` function maybe useful for this.

The following functions can be used for reporting errors.  These can
also be called by application code from within the ``page_handler``
function as well as ``template_fn`` and ``post_template_fn`` functions
to report errors, warnings, and debug messages in a uniform way.

```
def error(self, msg, trace=None)
```

Reports an error message.  The error will be added to ``Wtp.errors`` list and
printed to stdout.  The arguments are:
* msg (str) - the error message (need not include page title or section)
* trace (str or ``None``) - an optional stack trace giving more information
  about where the error occurred

```
def warning(self, msg, trace=None)
```

Reports a warning message.  The warning will be added to ``Wtp.warnings`` list
and printed to stdout.  The arguments are the same as for ``Wtp.error()``.

```
def debug(self, msg, trace=None)
```

Reports a debug message.  The message will be added to ``Wtp.debugs`` list
and printed to stdout.  The arguments are the same as for ``Wtp.error()``.

```
def to_return(self)
```

Produces a dictionary containing the error, warning, and debug
messages from ``Wtp``.  This would typically be called at the end of a
``page_handler`` function and the value returned along with whatever
data was extracted from that page.  The error lists are reset by
``Wtp.start_page()`` (including the implicit calls from
``Wtp.process()`` and ``Wtp.reprocess()``), so they should be saved
(e.g., by this call) for each page.  (Given the parallelism in
the processing of the pages, they cannot just be accumulated in the
subprocesses.)

The returned dictionary contains the following keys:
* ``errors`` - a list of dictionaries describing any error messages
* ``warnings`` - a list of dictionaries describing any warning messages
* ``debugs`` - a list of dictionaries describing any debug messages.

### class WikiNode(object)

The ``WikiNode`` class represents a parse tree node and is returned by
``Wtp.parse()``.  This object can be printed or converted to a string
and will display a human-readable format that is suitable for
debugging purposes (at least for small parse trees).

The ``WikiNode`` objects have the following fields:
* ``kind`` (NodeKind, see below) - The type of the node.  This determines
  how to interpret the other fields.
* ``children`` (list) - Contents of the node.  This is generally used when
  the node has arbitrary size content, such as subsections, list items/sublists,
  other HTML tags, etc.
* ``args`` (list or str, depending on ``kind``) - Direct arguments to the
  node.  This is used, for example, for templates, template arguments, parser
  function arguments, and link arguments, in which case this is a list.
  For some node types (e.g., list, list item, and HTML tag), this is
  directly a string.
* ``attrs`` - A dictionary containing HTML attributes or a definition list
  definition (under the ``def`` key).

### class NodeKind(enum.Enum)

The ``NodeKind`` type is an enumerated value for parse tree (``WikiNode``)
node types.  Currently the following values are used (typically these
need to be prefixed by ``Nodekind.``, e.g., ``NodeKind.LEVEL2``):
* ``ROOT`` - The root node of the parse tree.
* ``LEVEL2`` - Level 2 subtitle (==).  The ``args`` field contains the title
  and ``children`` field contains any contents that are within this section
* ``LEVEL3`` - Level 3 subtitle (===)
* ``LEVEL4`` - Level 4 subtitle (====)
* ``LEVEL5`` - Level 5 subtitle (=====)
* ``LEVEL6`` - Level 6 subtitle (======)
* ``ITALIC`` - Italic, content is in ``children``
* ``BOLD`` - Bold, content is in ``children``
* ``HLINE`` - A horizontal line (no arguments or children)
* ``LIST`` - Indicates a list.  Each list and sublist will start with
  this kind of node.  ``args`` will contain the prefix used to open the
  list (e.g., ``"##"`` - note this is stored directly as a string
  in ``args``).  List items will be stored in ``children``.
* ``LIST_ITEM`` - A list item in the children of a ``LIST`` node.  ``args``
  is the prefix used to open the list item (same as for the ``LIST`` node).
  The contents of the list item (including any possible sublists) are in
  ``children``.  If the list is a definition list (i.e., the prefix ends
  in ``";"``), then ``children`` contains the item label to be defined
  and ``attrs["def"]`` contains the definition.
* ``PREFORMATTED`` - Preformatted text where markup is interpreted.  Content
  is in ``children``.  This is used for lines starting with a space in
  wikitext.
* ``PRE`` - Preformatted text where markup is not interpreted.  Content
  is in ``children``.  This is indicated in wikitext by
  &lt;pre&gt;...&lt;/pre&gt;.
* ``LINK`` - An internal wikimedia link ([[...]] in wikitext).  The link
  arguments are in ``args``.  This tag is also used for media inclusion.
  Links with a trailing word end immediately after the link have the trailing
  part in ``children``.
* ``TEMPLATE`` - A template call (transclusion).  Template name is in the
  first argument and template arguments in subsequent arguments in ``args``.
  The ``children`` field is not used.  In wikitext templates are marked up
  as {{name|arg1|arg2|...}}.
* ``TEMPLATE_ARG`` - A template argument.  The argument name is in the first
  item in ``args`` followed by any subsequet arguments (normally at most two
  items, but I've seen arguments with more - probably an error in those
  template definitions).  The ``children`` field is not used.  In wikitext
  template arguments are marked up as {{{name|defval}}}.
* ``PARSER_FN`` - A parser function invocation.  This is also used for built-in
  variables such as {{PAGENAME}}.  The parser function name is in the
  first element of ``args`` and parser function arguments in subsequent
  elements.
* ``URL`` - An external URL. The first argument is the URL.  The second
  optional argument (in ``args``) is the display text.  The ``children``
  field is not used.
* ``TABLE`` - A table.  Content is in ``children``.  In wikitext, a table
  is encoded as {| ... |}.
* ``TABLE_CAPTION`` - A table caption.  This can only occur under
  ``TABLE``.  The content is in ``children``.  The ``attrs`` field contains
  a dictionary of any HTML attributes given to the table.
* ``TABLE_ROW`` - A table row.  This can only occur under ``TABLE``.  The
  content is in ``children`` (normally the content would be ``TABLE_CELL``
  or ``TABLE_HEADER_CELL`` nodes).  The ``attrs`` field contains a dictionary
  of any HTML attributes given to the table row.
* ``TABLE_HEADER_CELL`` - A table header cell.  This can only occur under
  ``TABLE_ROW``.  Content is in children.  The ``attrs`` field contains
  a dictionary of any HTML attributes given to the table row.
* ``TABLE_CELL`` - A table cell.  This can only occur under ``TABLE_ROW``.
  Content is in ``children``.  The ``attrs`` field contains a dictionary
  of any HTML attributes given to the table row.
* ``MAGIC_WORD`` - A MediaWiki magic word.  The magic word is assigned
  directly to ``args`` as a string (i.e., not in a list).  ``children`` is
  not used.  An example of a magic word would be ``__NOTOC__``.
* ``HTML`` - A HTML tag (or a matched pair of HTML tags).  ``args`` is the
  name of the HTML tag directly (not in a list and always without a slash).
  ``attrs`` is set to a dictionary of any HTML attributes from the tag.
  The contents of the HTML tag is in ``children``.

## Expected performance

This can generally process a few Wiktionary pages second per processor
core, including expansion of all templates, Lua macros, parsing the
full page, and analyzing the parse.  On a multi-core machine, this can
generally process a few dozen to a few hundred pages per second,
depending on the speed and the number of the cores.

Most of the processing effort goes to expanding Lua macros.  You can
elect not to expand Lua macros, but they are used extensively in
Wiktionary and for important information.  Expanding templates and Lua
macros allows much more robust and complete data extraction, but does
not come cheap.

## Contributing and bug reports

Please create an issue on github to report bugs or to contribute!


