Extension APIのサンプルコードを実行してみる
《 初回公開：2022/03/26 , 最終更新：未 》
「Python-MarkdownのためのExtensionを記述する」のサンプルコードを実際に実行してみる。
【 目次 】
各プロセッサの登録状況と優先度は？
独自のExtensionを作成しプロセッサをRegistryに登録するには、プロセッサの優先度をregisterのpriority引数を使って指定する必要がある。
しかし、このためには現状どのようなプロセッサがどのような優先度において登録されているかを知る必要があるように思う。
このため、Registryのregisterメソッドなどを私なりに解析して、各プロセッサの優先度がどのように登録されているか調べるためのコードを、なかば強引につくってみた。
#! python3
import markdown
extensions = ["extra", "codehilite", "fenced_code", "toc", "admonition", "meta"]
md = markdown.Markdown(extensions=extensions)
registrys = [
("Preprocessors", md.preprocessors),
("Block Processors", md.parser.blockprocessors),
("Tree Processors", md.treeprocessors),
("Inline Processors", md.inlinePatterns),
("Postprocessors", md.postprocessors),
]
for (name, registry) in registrys:
print()
print(f"processor_name: {name}")
for priorityItem in registry._priority:
print(f"name: {priorityItem.name}, priority: {priorityItem.priority}, type: {type(registry._data[priorityItem.name]).__name__}")
実行結果
processor_name: Preprocessors name: normalize_whitespace, priority: 30, type: NormalizeWhitespace name: html_block, priority: 20, type: HtmlBlockPreprocessor name: fenced_code_block, priority: 25, type: FencedBlockPreprocessor name: meta, priority: 27, type: MetaPreprocessor processor_name: Block Processors name: empty, priority: 100, type: EmptyBlockProcessor name: indent, priority: 90, type: ListIndentProcessor name: code, priority: 80, type: CodeBlockProcessor name: hashheader, priority: 70, type: HashHeaderProcessor name: setextheader, priority: 60, type: SetextHeaderProcessor name: hr, priority: 50, type: HRProcessor name: olist, priority: 40, type: OListProcessor name: ulist, priority: 30, type: UListProcessor name: quote, priority: 20, type: BlockQuoteProcessor name: reference, priority: 15, type: ReferenceProcessor name: paragraph, priority: 10, type: ParagraphProcessor name: footnote, priority: 17, type: FootnoteBlockProcessor name: defindent, priority: 85, type: DefListIndentProcessor name: deflist, priority: 25, type: DefListProcessor name: table, priority: 75, type: TableProcessor name: abbr, priority: 16, type: AbbrPreprocessor name: markdown_block, priority: 105, type: MarkdownInHtmlProcessor name: admonition, priority: 105, type: AdmonitionProcessor processor_name: Tree Processors name: inline, priority: 20, type: InlineProcessor name: prettify, priority: 10, type: PrettifyTreeprocessor name: footnote, priority: 50, type: FootnoteTreeprocessor name: footnote-duplicate, priority: 15, type: FootnotePostTreeprocessor name: attr_list, priority: 8, type: AttrListTreeprocessor name: hilite, priority: 30, type: HiliteTreeprocessor name: toc, priority: 5, type: TocTreeprocessor processor_name: Inline Processors name: backtick, priority: 190, type: BacktickInlineProcessor name: escape, priority: 180, type: EscapeInlineProcessor name: reference, priority: 170, type: ReferenceInlineProcessor name: link, priority: 160, type: LinkInlineProcessor name: image_link, priority: 150, type: ImageInlineProcessor name: image_reference, priority: 140, type: ImageReferenceInlineProcessor name: short_reference, priority: 130, type: ShortReferenceInlineProcessor name: short_image_ref, priority: 125, type: ShortImageReferenceInlineProcessor name: autolink, priority: 120, type: AutolinkInlineProcessor name: automail, priority: 110, type: AutomailInlineProcessor name: linebreak, priority: 100, type: SubstituteTagInlineProcessor name: html, priority: 90, type: HtmlInlineProcessor name: entity, priority: 80, type: HtmlInlineProcessor name: not_strong, priority: 70, type: SimpleTextInlineProcessor name: em_strong, priority: 60, type: AsteriskProcessor name: em_strong2, priority: 50, type: UnderscoreProcessor name: footnote, priority: 175, type: FootnoteInlineProcessor processor_name: Postprocessors name: footnote, priority: 25, type: FootnotePostprocessor name: amp_substitute, priority: 20, type: AndSubstitutePostprocessor name: unescape, priority: 10, type: UnescapePostprocessor name: raw_html, priority: 30, type: MarkdownInHTMLPostprocessor
Preprocessorのサンプルコードを実行してみる
NoRenderクラスを含むnorender_extentionモジュールのフルコードは
norender_extention.py
from markdown.extensions import Extension
from markdown.preprocessors import Preprocessor
import re
class NoRenderPreprocessor(Preprocessor):
""" Skip any line with words 'NO RENDER' in it. """
def run(self, lines):
new_lines = []
for line in lines:
m = re.search("NO RENDER", line)
if not m:
# any line without NO RENDER is passed through
new_lines.append(line)
return new_lines
class NoRenderExtension (Extension):
def extendMarkdown(self, md):
md.preprocessors.register(NoRenderPreprocessor(md), 'NoRender', 40)
def makeExtension(**kwargs):
return NoRenderExtension(**kwargs)
このnorender_extentionをテストしてみる。
norender_extention_test.py
import markdown
makedown_text = u'''
ドキュメントタイトル
===================
# NO RENDER
Markdownについては
- [MarkdownでHTMLを簡単に - 愚鈍人](http://ichitcltk.hustle.ne.jp/gudon2/index.php?pageType=file&id=markdown_memo)
****NO RENDER****
- [MarkdownでHTMLを簡単に - Sublime Tex 編 - 愚鈍人](http://ichitcltk.hustle.ne.jp/gudon2/index.php?pageType=file&id=sublime_markdown)
'''
extensions = ["norender_extention",]
print(markdown.Markdown(extensions=extensions).convert(makedown_text))
実行結果
<h1>ドキュメントタイトル</h1>
<p>Markdownについては</p>
<ul>
<li><a href="http://ichitcltk.hustle.ne.jp/gudon2/index.php?pageType=file&id=markdown_memo">MarkdownでHTMLを簡単に - 愚鈍人</a></li>
<li><a href="http://ichitcltk.hustle.ne.jp/gudon2/index.php?pageType=file&id=sublime_markdown">MarkdownでHTMLを簡単に - Sublime Tex 編 - 愚鈍人</a></li>
</ul>
BlockProcessorのサンプルコードを実行してみる
box_extentionモジュールのフルコードは
box_extention.py
from markdown.extensions import Extension
from markdown.blockprocessors import BlockProcessor
import re
import xml.etree.ElementTree as etree
class BoxBlockProcessor(BlockProcessor):
RE_FENCE_START = r'^ *!{3,} *\n' # start line, e.g., ` !!!! `
RE_FENCE_END = r'\n *!{3,}\s*$' # last non-blank line, e.g, '!!!\n \n\n'
def test(self, parent, block):
return re.match(self.RE_FENCE_START, block)
def run(self, parent, blocks):
original_block = blocks[0]
blocks[0] = re.sub(self.RE_FENCE_START, '', blocks[0])
# Find block with ending fence
for block_num, block in enumerate(blocks):
if re.search(self.RE_FENCE_END, block):
# remove fence
blocks[block_num] = re.sub(self.RE_FENCE_END, '', block)
# render fenced area inside a new div
e = etree.SubElement(parent, 'div')
e.set('style', 'display: inline-block; border: 1px solid red;')
self.parser.parseBlocks(e, blocks[0:block_num + 1])
# remove used blocks
for i in range(0, block_num + 1):
blocks.pop(0)
return True # or could have had no return statement
# No closing marker! Restore and do nothing
blocks[0] = original_block
return False # equivalent to our test() routine returning False
class BoxExtension(Extension):
def extendMarkdown(self, md):
md.parser.blockprocessors.register(BoxBlockProcessor(md.parser), 'box', 175)
def makeExtension(**kwargs):
return BoxExtension(**kwargs)
このbox_extentionをテストしてみる。
box_extention_test.py
import markdown
makedown_text = '''
A regular paragraph of text.
!!!!!
First paragraph of wrapped text.
Second Paragraph of **wrapped** text.
!!!!!
Another regular paragraph of text.
'''
extensions = ["box_extention",]
print(markdown.Markdown(extensions=extensions).convert(makedown_text))
実行結果
<p>A regular paragraph of text.</p>
<div style="display: inline-block; border: 1px solid red;">
<p>First paragraph of wrapped text.</p>
<p>Second Paragraph of <strong>wrapped</strong> text.</p>
</div>
<p>Another regular paragraph of text.</p>
Treeprocessorのサンプルコード
Treeprocessorのサンプルのサンプルコードについては
を参照。
InlineProcessorのサンプルコード
del_extensionモジュールのフルコードは
del_extension.py
from markdown.inlinepatterns import SimpleTagInlineProcessor
from markdown.extensions import Extension
class DelExtension(Extension):
def extendMarkdown(self, md):
md.inlinePatterns.register(SimpleTagInlineProcessor(r'()--(.*?)--', 'del'), 'del', 175)
def makeExtension(**kwargs):
return DelExtension(**kwargs)
このdel_extentionをテストするコードは。
del_extension_test.py
import markdown
makedown_text = '''
First line of the block.
This is --strike one--.
This is --strike two--.
End of the block.
'''
extensions = ["del_extension",]
print(markdown.Markdown(extensions=extensions).convert(makedown_text))
実行結果
<p>First line of the block.
This is <del>strike one</del>.
This is <del>strike two</del>.
End of the block.</p>
Patternクラスを使ったサンプルコード
PatternクラスはInlineProcessorクラスに取って代わられているようで、使う必要はなさそうであるが。
一応、Patternクラスを使ったサンプルコードは
が参考になると思う。
これを参考にEmphasisPatternのコードを補完してみると、
(実際には*emphasis*の機能はPython-Markdownに組み込まれており、このコードは仮のコードであり実用には適さないが)
from markdown.inlinepatterns import Pattern
from markdown.extensions import Extension
import xml.etree.ElementTree as etree
MYPATTERN = r'\*([^*]+)\*'
class EmphasisPattern(Pattern):
def handleMatch(self, m):
el = etree.Element('em')
el.text = m.group(2)
return el
class EmphasisExtension(Extension):
def extendMarkdown(self, md):
emphasis = EmphasisPattern(MYPATTERN)
md.inlinePatterns.register(emphasis, 'emphasis', 175)
def makeExtension(**kwargs):
return EmphasisPattern(**kwargs)
ポストプロセッサのサンプルコード
show_actual_html_extentionモジュールのフルコードは
show_actual_html_extention.py
from markdown.extensions import Extension
from markdown.postprocessors import Postprocessor
import re
class ShowActualHtmlPostprocesor(Postprocessor):
""" Wrap entire output in <pre> tags as a diagnostic. """
def run(self, text):
return '<pre>\n' + re.sub('<', '<', text) + '</pre>\n'
class ShowActualHtmlExtension(Extension):
def extendMarkdown(self, md):
md.postprocessors.register(ShowActualHtmlPostprocesor(), 'show_actual_html', 40)
def makeExtension(**kwargs):
return ShowActualHtmlExtension(**kwargs)
このdel_extentionをテストするコードは。
show_actual_html_extention_test.py
import markdown
makedown_text = u'''
ドキュメントタイトル
===================
Markdownについては
- [MarkdownでHTMLを簡単に - 愚鈍人](http://ichitcltk.hustle.ne.jp/gudon2/index.php?pageType=file&id=markdown_memo)
- [MarkdownでHTMLを簡単に - Sublime Tex 編 - 愚鈍人](http://ichitcltk.hustle.ne.jp/gudon2/index.php?pageType=file&id=sublime_markdown)
'''
extensions = ["show_actual_html_extention",]
print(markdown.Markdown(extensions=extensions).convert(makedown_text))
実行結果
<pre>
<h1>ドキュメントタイトル</h1>
<p>Markdownについては</p>
<ul>
<li><a href="http://ichitcltk.hustle.ne.jp/gudon2/index.php?pageType=file&id=markdown_memo">MarkdownでHTMLを簡単に - 愚鈍人</a></li>
<li><a href="http://ichitcltk.hustle.ne.jp/gudon2/index.php?pageType=file&id=sublime_markdown">MarkdownでHTMLを簡単に - Sublime Tex 編 - 愚鈍人</a></li>
</ul></pre>