BeautifulSoup的成员结构

>>> dir(soup)
['ASCII_SPACES', 'DEFAULT_BUILDER_FEATURES', 'HTML_FORMATTERS', 'ROOT_TAG_NAME',
'XML_FORMATTERS', '__bool__', '__call__', '__class__', '__contains__', '__delat
tr__', '__delitem__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__',
'__ge__', '__getattr__', '__getattribute__', '__getitem__', '__gt__', '__hash__'
, '__init__', '__iter__', '__le__', '__len__', '__lt__', '__module__', '__ne__',
'__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setitem
__', '__sizeof__', '__str__', '__subclasshook__', '__unicode__', '__weakref__',
'_all_strings', '_attr_value_as_string', '_attribute_checker', '_feed', '_find_a
ll', '_find_one', '_formatter_for_name', '_is_xml', '_lastRecursiveChild', '_las
t_descendant', '_most_recent_element', '_popToTag', '_select_debug', '_selector_
combinators', '_should_pretty_print', '_tag_name_matches_and',
'append', 'attribselect_re', 'attrs', 'builder', 'can_be_empty_element', 'childGenerator', 'children', 'clear', 'contains_replacement_characters', 'contents', 'currentTag',
'current_data', 'declared_html_encoding', 'decode', 'decode_contents', 'decompose','descendants', 'encode', 'encode_contents', 'endData', 'extract', 'fetchNextSiblings',
'fetchParents', 'fetchPrevious', 'fetchPreviousSiblings', 'find', 'findAll', 'findAllNext', 'findAllPrevious', 'findChild', 'findChildren', 'findNext',
'findNextSibling', 'findNextSiblings', 'findParent', 'findParents', 'findPrevious', 'findPreviousSibling', 'findPreviousSiblings', 'find_all', 'find_all_next',
'find_all_previous', 'find_next', 'find_next_sibling', 'find_next_siblings', 'find_parent', 'find_parents', 'find_previous', 'find_previous_sibling', 'find_previous_siblings',
'format_string', 'get', 'getText', 'get_text', 'handle_data', 'handle_endtag', 'handle_starttag', 'has_attr', 'has_key', 'hidden', 'index', 'insert', 'insert_after',
'insert_before', 'isSelfClosing', 'is_empty_element', 'is_xml', 'markup', 'name', 'namespace', 'new_string', 'new_tag', 'next', 'nextGenerator', 'nextSibling', 'nextSiblingGenerator',
'next_element', 'next_elements', 'next_sibling', 'next_siblings', 'object_was_parsed', 'original_encoding', 'parent', 'parentGenerator', 'parents', 'parse_only', 'parserClass',
'parser_class', 'popTag', 'prefix', 'preserve_whitespace_tag_stack', 'prettify', 'previous', 'previousGenerator', 'previousSibling', 'previousSiblingGenerator', 'previous_element',
'previous_elements', 'previous_sibling', 'previous_siblings', 'pushTag', 'recursiveChildGenerator', 'renderContents', 'replaceWith', 'replaceWithChildren', 'replace_with',
'replace_with_children', 'reset', 'select', 'setup', 'string', 'strings', 'stripped_strings', 'tagStack', 'tag_name_re', 'text', 'unwrap', 'wrap']