Package lxml :: Package html :: Module diff |
[hide private]
[frames] | no frames]

# Module diff

source code

Classes | [hide private]
| DEL_START
| DEL_END
| NoDeletes Raised when the document no longer contains any pending deletes (DEL_START/DEL_END)
| token Represents a diffable token, generally a word that is displayed to the user. Opening tags are attached to this token when they are adjacent (pre_tags) and closing tags that follow the word (post_tags). Some exceptions occur when there are empty tags adjacent to a word, so there may be close tags in pre_tags, or open tags in post_tags.
| tag_token Represents a token that is actually a tag. Currently this is just the <img> tag, which takes up visible space just like a word but is only represented in a document by a tag.
| href_token Represents the href in an anchor tag. Unlike other words, we only show the href when it changes.
| InsensitiveSequenceMatcher Acts like SequenceMatcher, but tries not to find very small equal blocks amidst large spans of changes

Functions | [hide private]
default_markup(text, version) | source code
html_annotate(doclist, markup=<function default_markup at 0x315a758>) doclist should be ordered from oldest to newest, like: | source code
tokenize_annotated(doc, annotation) Tokenize a document and add an annotation attribute to each token | source code
html_annotate_merge_annotations(tokens_old, tokens_new) Merge the annotations from tokens_old into tokens_new, when the tokens in the new document already existed in the old document. | source code
copy_annotations(src, dest) Copy annotations from the tokens listed in src to the tokens in dest | source code
compress_tokens(tokens) Combine adjacent tokens when there is no HTML between the tokens, and they share an annotation | source code
compress_merge_back(tokens, tok) Merge tok into the last element of tokens (modifying the list of tokens in-place). | source code
markup_serialize_tokens(tokens, markup_func) Serialize the list of tokens into a list of text chunks, calling markup_func around text to add annotations. | source code
htmldiff(old_html, new_html) Do a diff of the old and new document. The documents are HTML fragments (str/UTF8 or unicode), they are not complete documents (i.e., no <html> tag). | source code
htmldiff_tokens(html1_tokens, html2_tokens) Does a diff on the tokens themselves, returning a list of text chunks (not tokens). | source code
expand_tokens(tokens, equal=False) Given a list of tokens, return a generator of the chunks of text for the data in the tokens. | source code
merge_insert(ins_chunks, doc) doc is the already-handled document (as a list of text chunks); here we add <ins>ins_chunks</ins> to the end of that. | source code
merge_delete(del_chunks, doc) Adds the text chunks in del_chunks to the document doc (another list of text chunks) with marker to show it is a delete. cleanup_delete later resolves these markers into <del> tags. | source code
cleanup_delete(chunks) Cleans up any DEL_START/DEL_END markers in the document, replacing them with <del></del>. To do this while keeping the document valid, it may need to drop some tags (either start or end tags). | source code
split_unbalanced(chunks) Return (unbalanced_start, balanced, unbalanced_end), where each is a list of text and tag chunks. | source code
split_delete(chunks) Returns (stuff_before_DEL_START, stuff_inside_DEL_START_END, stuff_after_DEL_END). Returns the first case found (there may be more DEL_STARTs in stuff_after_DEL_END). Raises NoDeletes if there's no DEL_START found. | source code
locate_unbalanced_start(unbalanced_start, pre_delete, post_delete) pre_delete and post_delete implicitly point to a place in the document (where the two were split). This moves that point (by popping items from one and pushing them onto the other). It moves the point to try to find a place where unbalanced_start applies. | source code
locate_unbalanced_end(unbalanced_end, pre_delete, post_delete) like locate_unbalanced_start, except handling end tags and possibly moving the point earlier in the document. | source code
tokenize(html, include_hrefs=True) Parse the given HTML and returns token objects (words with attached tags). | source code
parse_html(html, cleanup=True) Parses an HTML fragment, returning an lxml element. Note that the HTML will be wrapped in a <div> tag that was not in the original document. | source code
cleanup_html(html) This 'cleans' the HTML, meaning that any page structure is removed (only the contents of <body> are used, if there is any <body). Also <ins> and <del> tags are removed. | source code
fixup_chunks(chunks) This function takes a list of chunks and produces a list of tokens. | source code
flatten_el(el, include_hrefs, skip_tag=False) Takes an lxml element el, and generates all the text chunks for that tag. Each start tag is a chunk, each word is a chunk, and each end tag is a chunk. | source code
split_words(text) Splits some text into words. Includes trailing whitespace (one space) on each word when appropriate. | source code
start_tag(el) The text representation of the start tag for a tag. | source code
end_tag(el) The text representation of an end tag for a tag. Includes trailing whitespace when appropriate. | source code
is_word(tok) | source code
is_end_tag(tok) | source code
is_start_tag(tok) | source code
fixup_ins_del_tags(html) Given an html string, move any <ins> or <del> tags inside of any block-level elements, e.g. transform <ins><p>word</p></ins> to <p><ins>word</ins></p> | source code
serialize_html_fragment(el, skip_outer=False) Serialize a single lxml element as HTML. The serialized form includes the elements tail. | source code
_fixup_ins_del_tags(doc) fixup_ins_del_tags that works on an lxml document in-place | source code
_contains_block_level_tag(el) True if the element contains any block-level elements, like <p>, <td>, etc. | source code
_move_el_inside_block(el, tag) helper for _fixup_ins_del_tags; actually takes the <ins> etc tags and moves them inside any block-level tags. | source code
_merge_element_contents(el) Removes an element, but merges its contents into its place, e.g., given <p>Hi <i>there!</i></p>, if you remove the <i> element you get <p>Hi there!</p> | source code

Variables | [hide private]
| _body_re = `re.compile(r'`(?is)`<body.`*?`>')`
| _end_body_re = `re.compile(r'`(?is)`</body.`*?`>')`
| _ins_del_re = `re.compile(r'`(?is)`</`?``(`ins`|`del`)`.`*?`>')`
| end_whitespace_re = `re.compile(r'`[` \t\n\r`]`$')`
| empty_tags = ``(``'``param``'``,` `'``img``'``,` `'``area``'``,` `'``br``'``,` `'``basefont``'``,` `'``input``...``
| block_level_tags = ``(``'``address``'``,` `'``blockquote``'``,` `'``center``'``,` `'``dir``'``,` `...``
| block_level_container_tags = ``(``'``dd``'``,` `'``dt``'``,` `'``frameset``'``,` `'``li``'``,` `'``t``...``
| start_whitespace_re = `re.compile(r'^`[` \t\n\r`]`')`
| __package__ = ``'``lxml.html``'``

Function Details | [hide private]

### html_annotate(doclist, markup=<function default_markup at 0x315a758>) | source code
doclist should be ordered from oldest to newest, like:
    >>> version1 = 'Hello World'
    >>> version2 = 'Goodbye World'
    >>> print(html_annotate([(version1, 'version 1'),
    ...                      (version2, 'version 2')]))
    <span title="version 2">Goodbye</span> <span title="version 1">World</span>
> The documents must be fragments (str/UTF8 or unicode), not complete documents The markup argument is a function to markup the spans of words. This function is called like markup('Hello', 'version 2'), and returns HTML. The first argument is text and never includes any markup. The default uses a span with a title:
>     >>> print(default_markup('Some Text', 'by Joe'))
>     <span title="by Joe">Some Text</span>

### htmldiff(old_html, new_html) | source code
Do a diff of the old and new document. The documents are HTML fragments (str/UTF8 or unicode), they are not complete documents (i.e., no <html> tag). Returns HTML with <ins> and <del> tags added around the appropriate text. Markup is generally ignored, with the markup from new_html preserved, and possibly some markup from old_html (though it is considered acceptable to lose some of the old markup). Only the words in the HTML are diffed. The exception is <img> tags, which are treated like words, and the href attribute of <a> tags, which are noted inside the tag itself when there are changes.

### cleanup_delete(chunks) | source code
Cleans up any DEL_START/DEL_END markers in the document, replacing them with <del></del>. To do this while keeping the document valid, it may need to drop some tags (either start or end tags). It may also move the del into adjacent tags to try to move it to a similar location where it was originally located (e.g., moving a delete into preceding <div> tag, if the del looks like (DEL_START, 'Text</div>', DEL_END)

### split_unbalanced(chunks) | source code
Return (unbalanced_start, balanced, unbalanced_end), where each is a list of text and tag chunks. unbalanced_start is a list of all the tags that are opened, but not closed in this span. Similarly, unbalanced_end is a list of tags that are closed but were not opened. Extracting these might mean some reordering of the chunks.

### locate_unbalanced_start(unbalanced_start, pre_delete, post_delete) | source code
pre_delete and post_delete implicitly point to a place in the document (where the two were split). This moves that point (by popping items from one and pushing them onto the other). It moves the point to try to find a place where unbalanced_start applies. As an example:
    >>> unbalanced_start = ['<div>']
    >>> doc = ['<p>', 'Text', '</p>', '<div>', 'More Text', '</div>']
    >>> pre, post = doc[:3], doc[3:]
    >>> pre, post
    (['<p>', 'Text', '</p>'], ['<div>', 'More Text', '</div>'])
    >>> locate_unbalanced_start(unbalanced_start, pre, post)
    >>> pre, post
    (['<p>', 'Text', '</p>', '<div>'], ['More Text', '</div>'])
As you can see, we moved the point so that the dangling <div> that we found will be effectively replaced by the div in the original document. If this doesn't work out, we just throw away unbalanced_start without doing anything.

### tokenize(html, include_hrefs=True) | source code
Parse the given HTML and returns token objects (words with attached tags). This parses only the content of a page; anything in the head is ignored, and the <head> and <body> elements are themselves optional. The content is then parsed by lxml, which ensures the validity of the resulting parsed document (though lxml may make incorrect guesses when the markup is particular bad). <ins> and <del> tags are also eliminated from the document, as that gets confusing. If include_hrefs is true, then the href attribute of <a> tags is included as a special kind of diffable token.

### parse_html(html, cleanup=True) | source code
Parses an HTML fragment, returning an lxml element. Note that the HTML will be wrapped in a <div> tag that was not in the original document. If cleanup is true, make sure there's no <head> or <body>, and get rid of any <ins> and <del> tags.

### flatten_el(el, include_hrefs, skip_tag=False) | source code
Takes an lxml element el, and generates all the text chunks for that tag. Each start tag is a chunk, each word is a chunk, and each end tag is a chunk. If skip_tag is true, then the outermost container tag is not returned (just its contents).

### serialize_html_fragment(el, skip_outer=False) | source code
Serialize a single lxml element as HTML. The serialized form includes the elements tail. If skip_outer is true, then don't serialize the outermost tag

Variables Details | [hide private]

  ### empty_tags Value:
      ('param',
       'img',
       'area',
       'br',
       'basefont',
       'input',
       'base',
       'meta',
      ...

  ### block_level_tags Value:
      ('address',
       'blockquote',
       'center',
       'dir',
       'div',
       'dl',
       'fieldset',
       'form',
      ...

  ### block_level_container_tags Value:
      ('dd',
       'dt',
       'frameset',
       'li',
       'tbody',
       'td',
       'tfoot',
       'th',
      ...