ppcomp

Compare 2 files for Distributed Proofreaders users.

Introduction

Used to compare 2 files and generate a summary of the differences. Its goal is to look for discrepancies between the text and HTML versions produced at PGDP, ignoring many formatting and spacing differences.

The sources can be:

• A post-processed text file.
• A post-processed HTML file.
• An unprocessed text file from the Px or Fx rounds.
• A text or HTML file from an external source.

The text files are identified by the .txt extension, HTML files by the .htm, .html, or .xhtml extension, and a Px or Fx file by its "projectID" prefix.

It applies various transformations according to program options before passing the files to the Linux program dwdiff. There does not seem to be any Windows equivalent of dwdiff, it can only be run in a Windows Subsystem for Linux console.

Usage

Option	File type	Description
-h		Show usage
--ignore-case	All	Ignore case when comparing
--extract-footnotes	All	Extract and process footnotes separately
--suppress-footnote-tags	Text	Suppress [Footnote ?: ...] marks
--suppress-illustration-tags	Text	Suppress [Illustration: ...] marks
--suppress-sidenote-tags	Text	Suppress [Sidenote: ] marks
--ignore-format	Rounds	Silence formatting differences (<i>, <b>)
--suppress-proofers-notes	Rounds	Suppress [**proofreaders notes]
--regroup-split-words	Rounds	Regroup split wo- rds
--txt-cleanup-type TYPE	Rounds	Type of text cleaning -- (b)est effort [default], (n)one, (p)roofers
--css-add-illustration	HTML	Add [Illustration: ...] tags
--css-add-sidenote	HTML	Add [Sidenote: ...] tags
--css-smcap TYPE	HTML	Transform small caps into uppercase (U), lowercase (L) or title case (T)
--css-bold STR	HTML	Surround bold strings with this string [default '=']
--css CSS	HTML	Insert custom transformation CSS (can be multiple)
--css-no-default	HTML	Do not use default transformation CSS
--suppress-nbsp-num	HTML	Suppress non-breakable spaces (U+00A0) between numbers
--ignore-0-space	HTML	Suppress zero width space (U+200B)
--css-greek-title-plus	HTML	Use Greek transliteration from the title attribute
--simple-html	HTML	Process an html file and print the output (debug)

Requirements

ppcomp needs python 3 (not 2) to run, as well as the following python packages:

• lxml
• tinycss
• cssselect
• html5lib (used by lxml)

And the following command-line tool:

• dwdiff

Installation

To install on Linux (Debian or Ubuntu):

sudo apt-get install dwdiff

Use pip to install the packages. First, install pip for python3 if it's not already installed:

sudo apt-get install python3-pip

then install the needed packages:

pip install tinycss
pip install cssselect
pip install lxml
pip install html5lib

Usage

Comparing two files is easy:

./ppcomp/ppcomp.py file1.txt file2.html > result.html

or

python ppcomp/ppcomp.py file1.txt file2.html > result.html

Internally, ppcomp will transform both files to reduce insignificant differences. For instance, in the HTML version <i> and </i> will be transformed to "_" so that will not generate a diff. Internally, a CSS transformation engine will take care of the HTML.

Once both files are transformed, the diff happens (using dwdiff), then its output is transformed into HTML. This HTML result is then sent to the standard output where it can be redirected and finally loaded into a browser. There is a small notification at the top explaining the diffs.

Footnotes

If the two versions have footnotes, but they are not placed in the same spot (i.e., after each paragraph for the text, and at the end of the book for the HTML), they can be extracted and compared separately:

--extract-footnotes

Note that formatting of footnotes by processors varies widely, only a few variations are supported.

Tuning

By default, a few reasonable rules are applied to the HTML (See the definition of DEFAULT_TRANSFORM_CSS in the source code). However, it may be necessary to go further to reduce the amount of noise.

Currently, a few CSS targets are supported:

::before  -- add content before the tag
::after   -- add content after the tag

Some transformations are also supported:

text-transform -- transform the content to uppercase, lowercase, or title case
_replace_with_attr -- replace the whole content with the value of an attribute
text-replace -- replace a string inside content with another

--css Example

Footnote Anchors

By default footnote anchors are expected to be surrounded by brackets. If it is not the case in the HTML, this can be easily fixed with the following:

--css '.fnanchor:before { content: "["; } .fnanchor:after { content: "]"; }'

Footnote extraction styles supported

html: class="footnote"

<div class="footnote">
  <a id="Footnote_926" href="#FNanchor_926" class="label">[926]</a>
    Kidston (94), p. 250.
</div>

Text output from formatting rounds ("projectID" prefix)

[Footnote #: followed by 1 or more paragraphs, with end bracket, and possible *[Footnote: continuation blocks.

[Footnote A: The pamphlet has been copied <i>in extenso</i>, and will be found in the Appendix.]
    
Normal paragraph.
    
*[Footnote: foootnote continued.]

Text PP style 1

[#] following empty line (to avoid normal bracketed text), 1 or more paragraphs ending with the next footnote or 2 empty lines.

Paragraph text.
    
[926] Kidston (94), p. 250.

[927] Another footnote.

Another footnote paragraph.


Normal paragraph.