bazarr/libs/markdown/preprocessors.py

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"""
Python Markdown
A Python implementation of John Gruber's Markdown.
Documentation: https://python-markdown.github.io/
GitHub: https://github.com/Python-Markdown/markdown/
PyPI: https://pypi.org/project/Markdown/
Started by Manfred Stienstra (http://www.dwerg.net/).
Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
Currently maintained by Waylan Limberg (https://github.com/waylan),
Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
Copyright 2007-2018 The Python Markdown Project (v. 1.7 and later)
Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
Copyright 2004 Manfred Stienstra (the original version)
License: BSD (see LICENSE.md for details).
PRE-PROCESSORS
=============================================================================
Preprocessors work on source text before we start doing anything too
complicated.
"""
from . import util
from .htmlparser import HTMLExtractor
import re
def build_preprocessors(md, **kwargs):
""" Build the default set of preprocessors used by Markdown. """
preprocessors = util.Registry()
preprocessors.register(NormalizeWhitespace(md), 'normalize_whitespace', 30)
preprocessors.register(HtmlBlockPreprocessor(md), 'html_block', 20)
return preprocessors
class Preprocessor(util.Processor):
"""
Preprocessors are run after the text is broken into lines.
Each preprocessor implements a "run" method that takes a pointer to a
list of lines of the document, modifies it as necessary and returns
either the same pointer or a pointer to a new list.
Preprocessors must extend markdown.Preprocessor.
"""
def run(self, lines):
"""
Each subclass of Preprocessor should override the `run` method, which
takes the document as a list of strings split by newlines and returns
the (possibly modified) list of lines.
"""
pass # pragma: no cover
class NormalizeWhitespace(Preprocessor):
""" Normalize whitespace for consistent parsing. """
def run(self, lines):
source = '\n'.join(lines)
source = source.replace(util.STX, "").replace(util.ETX, "")
source = source.replace("\r\n", "\n").replace("\r", "\n") + "\n\n"
source = source.expandtabs(self.md.tab_length)
source = re.sub(r'(?<=\n) +\n', '\n', source)
return source.split('\n')
class HtmlBlockPreprocessor(Preprocessor):
"""Remove html blocks from the text and store them for later retrieval."""
def run(self, lines):
source = '\n'.join(lines)
parser = HTMLExtractor(self.md)
parser.feed(source)
parser.close()
return ''.join(parser.cleandoc).split('\n')