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https://github.com/5j9/wikitextparser

A Python library to parse MediaWiki WikiText
https://github.com/5j9/wikitextparser

mediawiki parsing python text-analysis

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A Python library to parse MediaWiki WikiText

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README

        

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==============
WikiTextParser
==============
.. Quick Start Guid

A simple to use WikiText parsing library for `MediaWiki `_.

The purpose is to allow users easily extract and/or manipulate templates, template parameters, parser functions, tables, external links, wikilinks, lists, etc. found in wikitexts.

.. contents:: Table of Contents

Installation
============

- Python 3.8+ is required
- ``pip install wikitextparser``

Usage
=====

.. code:: python

>>> import wikitextparser as wtp

WikiTextParser can detect sections, parser functions, templates, wiki links, external links, arguments, tables, wiki lists, and comments in your wikitext. The following sections are a quick overview of some of these functionalities.

You may also want to have a look at the test modules for more examples and probable pitfalls (expected failures).

Templates
---------

.. code:: python

>>> parsed = wtp.parse("{{text|value1{{text|value2}}}}")
>>> parsed.templates
[Template('{{text|value1{{text|value2}}}}'), Template('{{text|value2}}')]
>>> parsed.templates[0].arguments
[Argument("|value1{{text|value2}}")]
>>> parsed.templates[0].arguments[0].value = 'value3'
>>> print(parsed)
{{text|value3}}

The ``pformat`` method returns a pretty-print formatted string for templates:

.. code:: python

>>> parsed = wtp.parse('{{t1 |b=b|c=c| d={{t2|e=e|f=f}} }}')
>>> t1, t2 = parsed.templates
>>> print(t2.pformat())
{{t2
| e = e
| f = f
}}
>>> print(t1.pformat())
{{t1
| b = b
| c = c
| d = {{t2
| e = e
| f = f
}}
}}

``Template.rm_dup_args_safe`` and ``Template.rm_first_of_dup_args`` methods can be used to clean-up `pages using duplicate arguments in template calls `_:

.. code:: python

>>> t = wtp.Template('{{t|a=a|a=b|a=a}}')
>>> t.rm_dup_args_safe()
>>> t
Template('{{t|a=b|a=a}}')
>>> t = wtp.Template('{{t|a=a|a=b|a=a}}')
>>> t.rm_first_of_dup_args()
>>> t
Template('{{t|a=a}}')

Template parameters:

.. code:: python

>>> param = wtp.parse('{{{a|b}}}').parameters[0]
>>> param.name
'a'
>>> param.default
'b'
>>> param.default = 'c'
>>> param
Parameter('{{{a|c}}}')
>>> param.append_default('d')
>>> param
Parameter('{{{a|{{{d|c}}}}}}')

WikiLinks
---------

.. code:: python

>>> wl = wtp.parse('... [[title#fragmet|text]] ...').wikilinks[0]
>>> wl.title = 'new_title'
>>> wl.fragment = 'new_fragmet'
>>> wl.text = 'X'
>>> wl
WikiLink('[[new_title#new_fragmet|X]]')
>>> del wl.text
>>> wl
WikiLink('[[new_title#new_fragmet]]')

All WikiLink properties support get, set, and delete operations.

Sections
--------

.. code:: python

>>> parsed = wtp.parse("""
... == h2 ==
... t2
... === h3 ===
... t3
... === h3 ===
... t3
... == h22 ==
... t22
... {{text|value3}}
... [[Z|X]]
... """)
>>> parsed.sections
[Section('\n'),
Section('== h2 ==\nt2\n=== h3 ===\nt3\n=== h3 ===\nt3\n'),
Section('=== h3 ===\nt3\n'),
Section('=== h3 ===\nt3\n'),
Section('== h22 ==\nt22\n{{text|value3}}\n[[Z|X]]\n')]
>>> parsed.sections[1].title = 'newtitle'
>>> print(parsed)

==newtitle==
t2
=== h3 ===
t3
=== h3 ===
t3
== h22 ==
t22
{{text|value3}}
[[Z|X]]
>>> del parsed.sections[1].title
>>>> print(parsed)

t2
=== h3 ===
t3
=== h3 ===
t3
== h22 ==
t22
{{text|value3}}
[[Z|X]]

Tables
------

Extracting cell values of a table:

.. code:: python

>>> p = wtp.parse("""{|
... | Orange || Apple || more
... |-
... | Bread || Pie || more
... |-
... | Butter || Ice cream || and more
... |}""")
>>> p.tables[0].data()
[['Orange', 'Apple', 'more'],
['Bread', 'Pie', 'more'],
['Butter', 'Ice cream', 'and more']]

By default, values are arranged according to ``colspan`` and ``rowspan`` attributes:

.. code:: python

>>> t = wtp.Table("""{| class="wikitable sortable"
... |-
... ! a !! b !! c
... |-
... !colspan = "2" | d || e
... |-
... |}""")
>>> t.data()
[['a', 'b', 'c'], ['d', 'd', 'e']]
>>> t.data(span=False)
[['a', 'b', 'c'], ['d', 'e']]

Calling the ``cells`` method of a ``Table`` returns table cells as ``Cell`` objects. Cell objects provide methods for getting or setting each cell's attributes or values individually:

.. code:: python

>>> cell = t.cells(row=1, column=1)
>>> cell.attrs
{'colspan': '2'}
>>> cell.set('colspan', '3')
>>> print(t)
{| class="wikitable sortable"
|-
! a !! b !! c
|-
!colspan = "3" | d || e
|-
|}

HTML attributes of Table, Cell, and Tag objects are accessible via
``get_attr``, ``set_attr``, ``has_attr``, and ``del_attr`` methods.

Lists
-----

The ``get_lists`` method provides access to lists within the wikitext.

.. code:: python

>>> parsed = wtp.parse(
... 'text\n'
... '* list item a\n'
... '* list item b\n'
... '** sub-list of b\n'
... '* list item c\n'
... '** sub-list of b\n'
... 'text'
... )
>>> wikilist = parsed.get_lists()[0]
>>> wikilist.items
[' list item a', ' list item b', ' list item c']

The ``sublists`` method can be used to get all sub-lists of the current list or just sub-lists of specific items:

.. code:: python

>>> wikilist.sublists()
[WikiList('** sub-list of b\n'), WikiList('** sub-list of b\n')]
>>> wikilist.sublists(1)[0].items
[' sub-list of b']

It also has an optional ``pattern`` argument that works similar to ``lists``, except that the current list pattern will be automatically added to it as a prefix:

.. code:: python

>>> wikilist = wtp.WikiList('#a\n#b\n##ba\n#*bb\n#:bc\n#c', '\#')
>>> wikilist.sublists()
[WikiList('##ba\n'), WikiList('#*bb\n'), WikiList('#:bc\n')]
>>> wikilist.sublists(pattern='\*')
[WikiList('#*bb\n')]

Convert one type of list to another using the convert method. Specifying the starting pattern of the desired lists can facilitate finding them and improves the performance:

.. code:: python

>>> wl = wtp.WikiList(
... ':*A1\n:*#B1\n:*#B2\n:*:continuing A1\n:*A2',
... pattern=':\*'
... )
>>> print(wl)
:*A1
:*#B1
:*#B2
:*:continuing A1
:*A2
>>> wl.convert('#')
>>> print(wl)
#A1
##B1
##B2
#:continuing A1
#A2

Tags
----

Accessing HTML tags:

.. code:: python

>>> p = wtp.parse('textcitation\n')
>>> ref, references = p.get_tags()
>>> ref.name = 'X'
>>> ref
Tag('citation')
>>> references
Tag('')

WikiTextParser is able to handle common usages of HTML and extension tags. However it is not a fully-fledged HTML parser and may fail on edge cases or malformed HTML input. Please open an issue on github if you encounter bugs.

Miscellaneous
-------------
``parent`` and ``ancestors`` methods can be used to access a node's parent or ancestors respectively:

.. code:: python

>>> template_d = parse("{{a|{{b|{{c|{{d}}}}}}}}").templates[3]
>>> template_d.ancestors()
[Template('{{c|{{d}}}}'),
Template('{{b|{{c|{{d}}}}}}'),
Template('{{a|{{b|{{c|{{d}}}}}}}}')]
>>> template_d.parent()
Template('{{c|{{d}}}}')
>>> _.parent()
Template('{{b|{{c|{{d}}}}}}')
>>> _.parent()
Template('{{a|{{b|{{c|{{d}}}}}}}}')
>>> _.parent() # Returns None

Use the optional ``type_`` argument if looking for ancestors of a specific type:

.. code:: python

>>> parsed = parse('{{a|{{#if:{{b{{c}}}}}}}}')
>>> comment = parsed.comments[0]
>>> comment.ancestors(type_='ParserFunction')
[ParserFunction('{{#if:{{b{{c}}}}}}')]

To delete/remove any object from its parents use ``del object[:]`` or ``del object.string``.

The ``remove_markup`` function or ``plain_text`` method can be used to remove wiki markup:

.. code:: python

>>> from wikitextparser import remove_markup, parse
>>> s = "'''a''' [[b|c]] [[d]]"
>>> remove_markup(s)
'a c d'
>>> parse(s).plain_text()
'a c d'

Compared with mwparserfromhell
==============================

`mwparserfromhell `_ is a mature and widely used library with nearly the same purposes as ``wikitextparser``. The main reason leading me to create ``wikitextparser`` was that ``mwparserfromhell`` could not parse wikitext in certain situations that I needed it for. See mwparserfromhell's issues `40 `_, `42 `_, `88 `_, and other related issues. In many of those situation ``wikitextparser`` may be able to give you more acceptable results.

Also note that ``wikitextparser`` is still using 0.x.y version `meaning `_ that the API is not stable and may change in the future versions.

The tokenizer in ``mwparserfromhell`` is written in C. Tokenization in ``wikitextparser`` is mostly done using the ``regex`` library which is also in C.
I have not rigorously compared the two libraries in terms of performance, i.e. execution time and memory usage. In my limited experience, ``wikitextparser`` has a decent performance in realistic cases and should be able to compete and may even have little performance benefits in some situations.

If you have had a chance to compare these libraries in terms of performance or capabilities please share your experience by opening an issue on github.

Some of the unique features of ``wikitextparser`` are: Providing access to individual cells of each table, pretty-printing templates, a WikiList class with rudimentary methods to work with `lists `_, and a few other functions.

Known issues and limitations
============================

* The contents of templates/parameters are not known to offline parsers. For example an offline parser cannot know if the markup ``[[{{z|a}}]]`` should be treated as wikilink or not, it depends on the inner-workings of the ``{{z}}`` template. In these situations ``wikitextparser`` tries to use a best guess. ``[[{{z|a}}]]`` is treated as a wikilink (why else would anyone call a template inside wikilink markup, and even if it is not a wikilink, usually no harm is done).
* Localized namespace names are unknown, so for example ``[[File:...]]`` links are treated as normal wikilinks. ``mwparserfromhell`` has similar issue, see `#87 `_ and `#136 `_. As a workaround, `Pywikibot `_ can be used for determining the namespace.
* `Linktrails `_ are language dependant and are not supported. `Also not supported by mwparserfromhell `_. However given the trail pattern and knowing that ``wikilink.span[1]`` is the ending position of a wikilink, it is possible to compute a WikiLink's linktrail.
* Templates adjacent to external links are never considered part of the link. In reality, this depends on the contents of the template. Example: ``parse('http://example.com{{dead link}}').external_links[0].url == 'http://example.com'``
* List of valid `extension tags `_ depends on the extensions intalled on the wiki. The ``tags`` method currently only supports the ones on English Wikipedia. A configuration option might be added in the future to address this issue.
* ``wikitextparser`` currently does not provide an `ast.walk `_-like method yielding all descendant nodes.
* `Parser functions `_ and `magic words `_ are not evaluated.

Credits
=======
* `python `_
* `regex `_
* `wcwidth `_