What's New in Beautiful Soup

Release 3.0.6 (2008/04/26)

• Added a Tag.decompose() method that completely disconnects a tree or a subset of a tree, breaking it up into bite-sized pieces that are easy for the garbage collecter to collect.
• Got rid of a very old debug line that prevented chardet from working.
• Tag.extract() now returns the tag that was extracted.
• Tag.findNext() now does something with the keyword arguments you pass it instead of dropping them on the floor.
• Fixed a Unicode conversion bug.
• Fixed a bug that garbled some tags when rewriting them.

Release 3.0.5 (2007/12/12)

• Beautiful Soup is now licensed under a BSD-style license.
• Soup objects can now be pickled, and copied with copy.deepcopy.
• Tag.append now works properly on existing BS objects. (It wasn't originally intended for outside use, but it can be now.) (Giles Radford)
• Passing in a nonexistent encoding will no longer crash the parser on Python 2.4 (John Nagle).
• Fixed an underlying bug in SGMLParser that thinks ASCII has 255 characters instead of 127 (John Nagle).
• Entities are converted more consistently to Unicode characters.
• Entity references in attribute values are now converted to Unicode characters when appropriate. Numeric entities are always converted, because SGMLParser always converts them outside of attribute values.
• ALL_ENTITIES happens to just be the XHTML entities, so I renamed it to XHTML_ENTITIES.
• The regular expression for bare ampersands was too loose. In some cases ampersands were not being escaped. (Sam Ruby?)
• Non-breaking spaces and other special Unicode space characters are no longer folded to ASCII spaces. (Robert Leftwich)
• Information inside a TEXTAREA tag is now parsed literally, not as HTML tags. TEXTAREA now works exactly the same way as SCRIPT. (Zephyr Fang)

Release 3.0.4 (2007/04/10)

• Fixed a bug that crashed Unicode conversion in some cases.
• Fixed a bug that prevented UnicodeDammit from being used as a general-purpose data scrubber.
• Fixed some unit test failures when running against Python 2.5.
• When considering whether to convert smart quotes, UnicodeDammit now looks at the original encoding in a case-insensitive way.

Release 3.0.3 (2006/06/06)

• Beautiful Soup is now usable as a way to clean up invalid XML/HTML (be sure to pass in an appropriate value for convertEntities, or XML/HTML entities might stick around that aren't valid in HTML/XML). The result may not validate, but it should be good enough to not choke a real-world XML parser. Specifically, the output of a properly constructed soup object should always be valid as part of an XML document, but parts may be missing if they were missing in the original. As always, if the input is valid XML, the output will also be valid.

Release 3.0.2 (2006/06/02)

• Previously, Beautiful Soup correctly handled attribute values that contained embedded quotes (sometimes by escaping), but not other kinds of XML character. Now, it correctly handles or escapes all special XML characters in attribute values.
• I aliased methods to the 2.x names (fetch, find, findText, etc.) for backwards compatibility purposes. Those names are deprecated and if I ever do a 4.0 I will remove them. I will, I tell you!
• Fixed a bug where the findAll method wasn't passing along any keyword arguments.
• When run from the command line, Beautiful Soup now acts as an HTML pretty-printer, not an XML pretty-printer.

Release 3.0.1 (2006/05/30)

• Reintroduced the "fetch by CSS class" shortcut. I thought keyword arguments would replace it, but they don't. You can't call soup('a', class='foo') because class is a Python keyword.
• If Beautiful Soup encounters a meta tag that declares the encoding, but a SoupStrainer tells it not to parse that tag, Beautiful Soup will no longer try to rewrite the meta tag to mention the new encoding. Basically, this makes SoupStrainers work in real-world applications instead of crashing the parser.

Release 3.0.0 (2006/05/28), "Who would not give all else for two p"

• This release is not backward-compatible with previous releases. If you've got code written with a previous version of the library, go ahead and keep using it, unless one of the features mentioned here really makes your life easier. Since the library is self-contained, you can include an old copy of the library in your old applications, and use the new version for everything else.
• The documentation has been rewritten and greatly expanded with many more examples.
• Beautiful Soup autodetects the encoding of a document (or uses the one you specify), and converts it from its native encoding to Unicode. Internally, it only deals with Unicode strings. When you print out the document, it converts to UTF-8 (or another encoding you specify). [Doc reference]
• It's now easy to make large-scale changes to the parse tree without screwing up the navigation members. The methods are extract, replaceWith, and insert. [Doc reference. See also Improving Memory Usage with extract]
• Passing True in as an attribute value gives you tags that have any value for that attribute. You don't have to create a regular expression. Passing None for an attribute value gives you tags that don't have that attribute at all.
• Tag objects now know whether or not they're self-closing. This avoids the problem where Beautiful Soup thought that tags like <BR /> were self-closing even in XML documents. You can customize the self-closing tags for a parser object by passing them in as a list of selfClosingTags: you don't have to subclass anymore. [Doc reference]
• There's a new built-in parser, MinimalSoup, which has most of BeautifulSoup's HTML-specific rules, but no tag nesting rules. [Doc reference]
• You can use a SoupStrainer to tell Beautiful Soup to parse only part of a document. This saves time and memory, often making Beautiful Soup about as fast as a custom-built SGMLParser subclass. [Doc reference, SoupStrainer reference]
• You can (usually) use keyword arguments instead of passing a dictionary of attributes to a search method. That is, you can replace soup(args={"id" : "5"}) with soup(id="5"). You can still use args if (for instance) you need to find an attribute whose name clashes with the name of an argument to findAll. [Doc reference: **kwargs attrs]
• The method names have changed to the better method names used in Rubyful Soup. Instead of find methods and fetch methods, there are only find methods. Instead of a scheme where you can't remember which method finds one element and which one finds them all, we have find and findAll. In general, if the method name mentions All or a plural noun (eg. findNextSiblings), then it finds many elements method. Otherwise, it only finds one element. [Doc reference]
• Some of the argument names have been renamed for clarity. For instance avoidParserProblems is now parserMassage.
• Beautiful Soup no longer implements a feed method. You need to pass a string or a filehandle into the soup constructor, not with feed after the soup has been created. There is still a feed method, but it's the feed method implemented by SGMLParser and calling it will bypass Beautiful Soup and cause problems.
• The NavigableText class has been renamed to NavigableString. There is no NavigableUnicodeString anymore, because every string inside a Beautiful Soup parse tree is a Unicode string.
• findText and fetchText are gone. Just pass a text argument into find or findAll.
• Null was more trouble than it was worth, so I got rid of it. Anything that used to return Null now returns None.
• Special XML constructs like comments and CDATA now have their own NavigableString subclasses, instead of being treated as oddly-formed data. If you parse a document that contains CDATA and write it back out, the CDATA will still be there. [Doc reference]
• When you're parsing a document, you can get Beautiful Soup to convert XML or HTML entities into the corresponding Unicode characters. [Doc reference]

Release 2.1.1 (2005/09/18)

• Fixed a serious performance bug in BeautifulStoneSoup which was causing parsing to be incredibly slow.
• Corrected several entities that were previously being incorrectly translated from Microsoft smart-quote-like characters.
• Fixed a bug that was breaking text fetch.
• Fixed a bug that crashed the parser when text chunks that look like HTML tag names showed up within a SCRIPT tag.
• THEAD, TBODY, and TFOOT tags are now nestable within TABLE tags. Nested tables should parse more sensibly now.
• BASE is now considered a self-closing tag.

Release 2.1.0, "Game, or any other dish?" (2005/05/04)

• Added a wide variety of new search methods which, given a starting point inside the tree, follow a particular navigation member (like nextSibling) over and over again, looking for Tag and NavigableText objects that match certain criteria. The new methods are findNext, fetchNext, findPrevious, fetchPrevious, findNextSibling, fetchNextSiblings, findPreviousSibling, fetchPreviousSiblings, findParent, and fetchParents. All of these use the same basic code used by first and fetch, so you can pass your weird ways of matching things into these methods.
• The fetch method and its derivatives now accept a limit argument.
• You can now pass keyword arguments when calling a Tag object as though it were a method.
• Fixed a bug that caused all hand-created tags to share a single set of attributes.

Release 2.0.3 (2005/05/01)

• Fixed Python 2.2 support for iterators.
• Fixed a bug that gave the wrong representation to tags within quote tags like <script>.
• Took some code from Mark Pilgrim that treats CDATA declarations as data instead of ignoring them.
• Beautiful Soup's setup.py will now do an install even if the unit tests fail. It won't build a source distribution if the unit tests fail, so I can't release a new version unless they pass.

Release 2.0.2 (2005/04/16)

• Added the unit tests in a separate module, and packaged it with distutils.
• Fixed a bug that sometimes caused renderContents() to return a Unicode string even if there was no Unicode in the original string.
• Added the done() method, which closes all of the parser's open tags. It gets called automatically when you pass in some text to the constructor of a parser class; otherwise you must call it yourself.
• Reinstated some backwards compatibility with 1.x versions: referencing the string member of a NavigableText object returns the NavigableText object instead of throwing an error.

Release 2.0.1 (2005/04/12)

• Fixed a bug that caused bad results when you tried to reference a tag name shorter than 3 characters as a member of a Tag, eg. tag.table.td.
• Made sure all Tags have the 'hidden' attribute so that an attempt to access tag.hidden doesn't spawn an attempt to find a tag named 'hidden'.
• Fixed a bug in the comparison operator.

Release 2.0, "Who cares for fish?" (2005/04/10)

Beautiful Soup version 1 was very useful but also pretty stupid. I originally wrote it without noticing any of the problems inherent in trying to build a parse tree out of ambiguous HTML tags. This version solves all of those problems to my satisfaction. It also adds many new clever things to make up for the removal of the stupid things.

Parsing

• The parser logic has been greatly improved, and the BeautifulSoup class should much more reliably yield a parse tree that looks like what the page author intended. For a particular class of odd edge cases that now causes problems, there is a new class, ICantBelieveItsBeautifulSoup.
• By default, Beautiful Soup now performs some cleanup operations on text before parsing it. This is to avoid common problems with bad definitions and self-closing tags that crash SGMLParser. You can provide your own set of cleanup operations, or turn it off altogether. The cleanup operations include fixing self-closing tags that don't close, and replacing Microsoft smart quotes and similar characters with their HTML entity equivalents.
• You can now get a pretty-print version of parsed HTML to get a visual picture of how Beautiful Soup parses it, with the Tag.prettify() method.

Strings and Unicode

• There are separate NavigableText subclasses for ASCII and Unicode strings. These classes directly subclass the corresponding base data types. This means you can treat NavigableText objects as strings instead of having to call methods on them to get the strings.
• str() on a Tag always returns a string, and unicode() always returns Unicode. Previously it was inconsistent.

Tree traversal

• In a first() or fetch() call, the tag name or the desired value of an attribute can now be any of the following:
  • A string (matches that specific tag or that specific attribute value)
  • A list of strings (matches any tag or attribute value in the list)
  • A compiled regular expression object (matches any tag or attribute value that matches the regular expression)
  • A callable object that takes the Tag object or attribute value as a string. It returns None/false/empty string if the given string doesn't match, and any other value if it does.

  This is much easier to use than SQL-style wildcards (see, regular expressions are good for something). Because of this, I took out SQL-style wildcards. I'll put them back if someone complains, but their removal simplifies the code a lot.

• You can use fetch() and first() to search for text in the parse tree, not just tags. There are new alias methods fetchText() and firstText() designed for this purpose. As with searching for tags, you can pass in a string, a regular expression object, or a method to match your text.
• If you pass in something besides a map to the attrs argument of fetch() or first(), Beautiful Soup will assume you want to match that thing against the "class" attribute. When you're scraping well-structured HTML, this makes your code a lot cleaner.
• 1.x and 2.x both let you call a Tag object as a shorthand for fetch(). For instance, foo("bar") is a shorthand for foo.fetch("bar"). In 2.x, you can also access a specially-named member of a Tag object as a shorthand for first(). For instance, foo.barTag is a shorthand for foo.first("bar"). By chaining these shortcuts you traverse a tree in very little code: for header in soup.bodyTag.pTag.tableTag('th'):
• If an element relationship (like parent or next) doesn't apply to a tag, it'll now show up Null instead of None. first() will also return Null if you ask it for a nonexistent tag. Null is an object that's just like None, except you can do whatever you want to it and it'll give you Null instead of throwing an error.

  This lets you do tree traversals like soup.htmlTag.headTag.titleTag without having to worry if the intermediate stages are actually there. Previously, if there was no 'head' tag in the document, headTag in that instance would have been None, and accessing its 'titleTag' member would have thrown an AttributeError. Now, you can get what you want when it exists, and get Null when it doesn't, without having to do a lot of conditionals checking to see if every stage is None.

• There are two new relations between page elements: previousSibling and nextSibling. They reference the previous and next element at the same level of the parse tree. For instance, if you have HTML like this:

  <p><ul><li>Foo<br /><li>Bar</ul>

  The first 'li' tag has a previousSibling of Null and its nextSibling is the second 'li' tag. The second 'li' tag has a nextSibling of Null and its previousSibling is the first 'li' tag. The previousSibling of the 'ul' tag is the first 'p' tag. The nextSibling of 'Foo' is the 'br' tag.
• I took out the ability to use fetch() to find tags that have a specific list of contents. See, I can't even explain it well. It was really difficult to use, I never used it, and I don't think anyone else ever used it. To the extent anyone did, they can probably use fetchText() instead. If it turns out someone needs it I'll think of another solution.

Tree manipulation

• You can add new attributes to a tag, and delete attributes from a tag. In 1.x you could only change a tag's existing attributes.

Porting Considerations

There are three changes in 2.0 that break old code:

• In the post-1.2 release you could pass in a function into fetch(). The function took a string, the tag name. In 2.0, the function takes the actual Tag object.
• It's no longer to pass in SQL-style wildcards to fetch(). Use a regular expression instead.
• The different parsing algorithm means the parse tree may not be shaped like you expect. This will only actually affect you if your code uses one of the affected parts. I haven't run into this problem yet while porting my code.

Between 1.2 and 2.0

This is the release to get if you want Python 1.5 compatibility.

• The desired value of an attribute can now be any of the following:
  • A string
  • A string with SQL-style wildcards
  • A compiled RE object
  • A callable that returns None/false/empty string if the given value doesn't match, and any other value otherwise.

  This is much easier to use than SQL-style wildcards (see, regular expressions are good for something). Because of this, I no longer recommend you use SQL-style wildcards. They may go away in a future release to clean up the code.

• Made Beautiful Soup handle processing instructions as text instead of ignoring them.
• Applied patch from Richie Hindle (richie at entrian dot com) that makes tag.string a shorthand for tag.contents[0].string when the tag has only one string-owning child.
• Added still more nestable tags. The nestable tags thing won't work in a lot of cases and needs to be rethought.
• Fixed an edge case where searching for "%foo" would match any string shorter than "foo".

Release 1.2, "Who for such dainties would not stoop?" (2004/07/08)

• Applied patch from Ben Last (ben at benlast dot com) that made Tag.renderContents() correctly handle Unicode.
• Made BeautifulStoneSoup even dumber by making it not implicitly close a tag when another tag of the same type is encountered; only when an actual closing tag is encountered. This change courtesy of Fuzzy (mike at pcblokes dot com). BeautifulSoup still works as before.

Release 1.1, "Swimming in a hot tureen"

• Added more 'nestable' tags. Changed popping semantics so that when a nestable tag is encountered, tags are popped up to the previously encountered nestable tag (of whatever kind). I will revert this if enough people complain, but it should make more people's lives easier than harder. This enhancement was suggested by Anthony Baxter (anthony at interlink dot com dot au).

Release 1.0, "So rich and green" (2005/04/20)

Initial release.