Initial import of py-beautifulsoup4, a rewrite of py-beautifulsoup.
Changes compared to version 3 (in py-beautifulsoup):

= 4.1.0 (20120529) =

* Added experimental support for fixing Windows-1252 characters
  embedded in UTF-8 documents. (UnicodeDammit.detwingle())

* Fixed the handling of &quot; with the built-in parser. [bug=993871]

* Comments, processing instructions, document type declarations, and
  markup declarations are now treated as preformatted strings, the way
  CData blocks are. [bug=1001025]

* Fixed a bug with the lxml treebuilder that prevented the user from
  adding attributes to a tag that didn't originally have
  attributes. [bug=1002378] Thanks to Oliver Beattie for the patch.

* Fixed some edge-case bugs having to do with inserting an element
  into a tag it's already inside, and replacing one of a tag's
  children with another. [bug=997529]

* Added the ability to search for attribute values specified in UTF-8. [bug=1003974]

  This caused a major refactoring of the search code. All the tests
  pass, but it's possible that some searches will behave differently.

= 4.0.5 (20120427) =

* Added a new method, wrap(), which wraps an element in a tag.

* Renamed replace_with_children() to unwrap(), which is easier to
  understand and also the jQuery name of the function.

* Made encoding substitution in <meta> tags completely transparent (no
  more %SOUP-ENCODING%).

* Fixed a bug in decoding data that contained a byte-order mark, such
  as data encoded in UTF-16LE. [bug=988980]

* Fixed a bug that made the HTMLParser treebuilder generate XML
  definitions ending with two question marks instead of
  one. [bug=984258]

* Upon document generation, CData objects are no longer run through
  the formatter. [bug=988905]

* The test suite now passes when lxml is not installed, whether or not
  html5lib is installed. [bug=987004]

* Print a warning on HTMLParseErrors to let people know they should
  install a better parser library.

= 4.0.4 (20120416) =

* Fixed a bug that sometimes created disconnected trees.

* Fixed a bug with the string setter that moved a string around the
  tree instead of copying it. [bug=983050]

* Attribute values are now run through the provided output formatter.
  Previously they were always run through the 'minimal' formatter. In
  the future I may make it possible to specify different formatters
  for attribute values and strings, but for now, consistent behavior
  is better than inconsistent behavior. [bug=980237]

* Added the missing renderContents method from Beautiful Soup 3. Also
  added an encode_contents() method to go along with decode_contents().

* Give a more useful error when the user tries to run the Python 2
  version of BS under Python 3.

* UnicodeDammit can now convert Microsoft smart quotes to ASCII with
  UnicodeDammit(markup, smart_quotes_to="ascii").

= 4.0.3 (20120403) =

* Fixed a typo that caused some versions of Python 3 to convert the
  Beautiful Soup codebase incorrectly.

* Got rid of the 4.0.2 workaround for HTML documents--it was
  unnecessary and the workaround was triggering a (possibly different,
  but related) bug in lxml. [bug=972466]

= 4.0.2 (20120326) =

* Worked around a possible bug in lxml that prevents non-tiny XML
  documents from being parsed. [bug=963880, bug=963936]

* Fixed a bug where specifying `text` while also searching for a tag
  only worked if `text` wanted an exact string match. [bug=955942]

= 4.0.1 (20120314) =

* This is the first official release of Beautiful Soup 4. There is no
  4.0.0 release, to eliminate any possibility that packaging software
  might treat "4.0.0" as being an earlier version than "4.0.0b10".

* Brought BS up to date with the latest release of soupselect, adding
  CSS selector support for direct descendant matches and multiple CSS
  class matches.

= 4.0.0b10 (20120302) =

* Added support for simple CSS selectors, taken from the soupselect project.

* Fixed a crash when using html5lib. [bug=943246]

* In HTML5-style <meta charset="foo"> tags, the value of the "charset"
  attribute is now replaced with the appropriate encoding on
  output. [bug=942714]

* Fixed a bug that caused calling a tag to sometimes call find_all()
  with the wrong arguments. [bug=944426]

* For backwards compatibility, brought back the BeautifulStoneSoup
  class as a deprecated wrapper around BeautifulSoup.

= 4.0.0b9 (20120228) =

* Fixed the string representation of DOCTYPEs that have both a public
  ID and a system ID.

* Fixed the generated XML declaration.

* Renamed Tag.nsprefix to Tag.prefix, for consistency with
  NamespacedAttribute.

* Fixed a test failure that occured on Python 3.x when chardet was
  installed.

* Made prettify() return Unicode by default, so it will look nice on
  Python 3 when passed into print().

= 4.0.0b8 (20120224) =

* All tree builders now preserve namespace information in the
  documents they parse. If you use the html5lib parser or lxml's XML
  parser, you can access the namespace URL for a tag as tag.namespace.

  However, there is no special support for namespace-oriented
  searching or tree manipulation. When you search the tree, you need
  to use namespace prefixes exactly as they're used in the original
  document.

* The string representation of a DOCTYPE always ends in a newline.

* Issue a warning if the user tries to use a SoupStrainer in
  conjunction with the html5lib tree builder, which doesn't support
  them.

= 4.0.0b7 (20120223) =

* Upon decoding to string, any characters that can't be represented in
  your chosen encoding will be converted into numeric XML entity
  references.

* Issue a warning if characters were replaced with REPLACEMENT
  CHARACTER during Unicode conversion.

* Restored compatibility with Python 2.6.

* The install process no longer installs docs or auxillary text files.

* It's now possible to deepcopy a BeautifulSoup object created with
  Python's built-in HTML parser.

* About 100 unit tests that "test" the behavior of various parsers on
  invalid markup have been removed. Legitimate changes to those
  parsers caused these tests to fail, indicating that perhaps
  Beautiful Soup should not test the behavior of foreign
  libraries.

  The problematic unit tests have been reformulated as informational
  comparisons generated by the script
  scripts/demonstrate_parser_differences.py.

  This makes Beautiful Soup compatible with html5lib version 0.95 and
  future versions of HTMLParser.

= 4.0.0b6 (20120216) =

* Multi-valued attributes like "class" always have a list of values,
  even if there's only one value in the list.

* Added a number of multi-valued attributes defined in HTML5.

* Stopped generating a space before the slash that closes an
  empty-element tag. This may come back if I add a special XHTML mode
  (http://www.w3.org/TR/xhtml1/#C_2), but right now it's pretty
  useless.

* Passing text along with tag-specific arguments to a find* method:

   find("a", text="Click here")

  will find tags that contain the given text as their
  .string. Previously, the tag-specific arguments were ignored and
  only strings were searched.

* Fixed a bug that caused the html5lib tree builder to build a
  partially disconnected tree. Generally cleaned up the html5lib tree
  builder.

* If you restrict a multi-valued attribute like "class" to a string
  that contains spaces, Beautiful Soup will only consider it a match
  if the values correspond to that specific string.

= 4.0.0b5 (20120209) =

* Rationalized Beautiful Soup's treatment of CSS class. A tag
  belonging to multiple CSS classes is treated as having a list of
  values for the 'class' attribute. Searching for a CSS class will
  match *any* of the CSS classes.

  This actually affects all attributes that the HTML standard defines
  as taking multiple values (class, rel, rev, archive, accept-charset,
  and headers), but 'class' is by far the most common. [bug=41034]

* If you pass anything other than a dictionary as the second argument
  to one of the find* methods, it'll assume you want to use that
  object to search against a tag's CSS classes. Previously this only
  worked if you passed in a string.

* Fixed a bug that caused a crash when you passed a dictionary as an
  attribute value (possibly because you mistyped "attrs"). [bug=842419]

* Unicode, Dammit now detects the encoding in HTML 5-style <meta> tags
  like <meta charset="utf-8" />. [bug=837268]

* If Unicode, Dammit can't figure out a consistent encoding for a
  page, it will try each of its guesses again, with errors="replace"
  instead of errors="strict". This may mean that some data gets
  replaced with REPLACEMENT CHARACTER, but at least most of it will
  get turned into Unicode. [bug=754903]

* Patched over a bug in html5lib (?) that was crashing Beautiful Soup
  on certain kinds of markup. [bug=838800]

* Fixed a bug that wrecked the tree if you replaced an element with an
  empty string. [bug=728697]

* Improved Unicode, Dammit's behavior when you give it Unicode to
  begin with.

= 4.0.0b4 (20120208) =

* Added BeautifulSoup.new_string() to go along with BeautifulSoup.new_tag()

* BeautifulSoup.new_tag() will follow the rules of whatever
  tree-builder was used to create the original BeautifulSoup object. A
  new <p> tag will look like "<p />" if the soup object was created to
  parse XML, but it will look like "<p></p>" if the soup object was
  created to parse HTML.

* We pass in strict=False to html.parser on Python 3, greatly
  improving html.parser's ability to handle bad HTML.

* We also monkeypatch a serious bug in html.parser that made
  strict=False disastrous on Python 3.2.2.

* Replaced the "substitute_html_entities" argument with the
  more general "formatter" argument.

* Bare ampersands and angle brackets are always converted to XML
  entities unless the user prevents it.

* Added PageElement.insert_before() and PageElement.insert_after(),
  which let you put an element into the parse tree with respect to
  some other element.

* Raise an exception when the user tries to do something nonsensical
  like insert a tag into itself.


= 4.0.0b3 (20120203) =

Beautiful Soup 4 is a nearly-complete rewrite that removes Beautiful
Soup's custom HTML parser in favor of a system that lets you write a
little glue code and plug in any HTML or XML parser you want.

Beautiful Soup 4.0 comes with glue code for four parsers:

 * Python's standard HTMLParser (html.parser in Python 3)
 * lxml's HTML and XML parsers
 * html5lib's HTML parser

HTMLParser is the default, but I recommend you install lxml if you
can.

For complete documentation, see the Sphinx documentation in
bs4/doc/source/. What follows is a summary of the changes from
Beautiful Soup 3.

=== The module name has changed ===

Previously you imported the BeautifulSoup class from a module also
called BeautifulSoup. To save keystrokes and make it clear which
version of the API is in use, the module is now called 'bs4':

    >>> from bs4 import BeautifulSoup

=== It works with Python 3 ===

Beautiful Soup 3.1.0 worked with Python 3, but the parser it used was
so bad that it barely worked at all. Beautiful Soup 4 works with
Python 3, and since its parser is pluggable, you don't sacrifice
quality.

Special thanks to Thomas Kluyver and Ezio Melotti for getting Python 3
support to the finish line. Ezio Melotti is also to thank for greatly
improving the HTML parser that comes with Python 3.2.

=== CDATA sections are normal text, if they're understood at all. ===

Currently, the lxml and html5lib HTML parsers ignore CDATA sections in
markup:

 <p><![CDATA[foo]]></p> => <p></p>

A future version of html5lib will turn CDATA sections into text nodes,
but only within tags like <svg> and <math>:

 <svg><![CDATA[foo]]></svg> => <p>foo</p>

The default XML parser (which uses lxml behind the scenes) turns CDATA
sections into ordinary text elements:

 <p><![CDATA[foo]]></p> => <p>foo</p>

In theory it's possible to preserve the CDATA sections when using the
XML parser, but I don't see how to get it to work in practice.

=== Miscellaneous other stuff ===

If the BeautifulSoup instance has .is_xml set to True, an appropriate
XML declaration will be emitted when the tree is transformed into a
string:

    <?xml version="1.0" encoding="utf-8">
    <markup>
     ...
    </markup>

The ['lxml', 'xml'] tree builder sets .is_xml to True; the other tree
builders set it to False. If you want to parse XHTML with an HTML
parser, you can set it manually.