Package lxml :: Package html :: Module soupparser |
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# Source Code for Module lxml.html.soupparser

      1  __doc__ = """External interface to the BeautifulSoup HTML parser.
      2  """
      3
      4  __all__ = ["fromstring", "parse", "convert_tree"]
      5
      6  from lxml import etree, html
      7  from BeautifulSoup import \
      8       BeautifulSoup, Tag, Comment, ProcessingInstruction, NavigableString
      9
     10
     11 -def fromstring(data, beautifulsoup=None, makeelement=None, **bsargs):
     12      """Parse a string of HTML data into an Element tree using the
     13      BeautifulSoup parser.
     14
     15      Returns the root ``<html>`` Element of the tree.
     16
     17      You can pass a different BeautifulSoup parser through the
     18      `beautifulsoup` keyword, and a diffent Element factory function
     19      through the `makeelement` keyword.  By default, the standard
     20      ``BeautifulSoup`` class and the default factory of `lxml.html` are
     21      used.
     22      """
     23      return _parse(data, beautifulsoup, makeelement, **bsargs)
     24
     25 -def parse(file, beautifulsoup=None, makeelement=None, **bsargs):
     26      """Parse a file into an ElemenTree using the BeautifulSoup parser.
     27
     28      You can pass a different BeautifulSoup parser through the
     29      `beautifulsoup` keyword, and a diffent Element factory function
     30      through the `makeelement` keyword.  By default, the standard
     31      ``BeautifulSoup`` class and the default factory of `lxml.html` are
     32      used.
     33      """
     34      if not hasattr(file, 'read'):
     35          file = open(file)
     36      root = _parse(file, beautifulsoup, makeelement, **bsargs)
     37      return etree.ElementTree(root)
     38
     39 -def convert_tree(beautiful_soup_tree, makeelement=None):
     40      """Convert a BeautifulSoup tree to a list of Element trees.
     41
     42      Returns a list instead of a single root Element to support
     43      HTML-like soup with more than one root element.
     44
     45      You can pass a different Element factory through the `makeelement`
     46      keyword.
     47      """
     48      if makeelement is None:
     49          makeelement = html.html_parser.makeelement
     50      root = _convert_tree(beautiful_soup_tree, makeelement)
     51      children = root.getchildren()
     52      for child in children:
     53          root.remove(child)
     54      return children
     55
     56
     57  # helpers
     58
     59 -def _parse(source, beautifulsoup, makeelement, **bsargs):
     60      if beautifulsoup is None:
     61          beautifulsoup = BeautifulSoup
     62      if makeelement is None:
     63          makeelement = html.html_parser.makeelement
     64      if 'convertEntities' not in bsargs:
     65          bsargs['convertEntities'] = 'html'
     66      tree = beautifulsoup(source, **bsargs)
     67      root = _convert_tree(tree, makeelement)
     68      # from ET: wrap the document in a html root element, if necessary
     69      if len(root) == 1 and root[0].tag == "html":
     70          return root[0]
     71      root.tag = "html"
     72      return root
     73
     74 -def _convert_tree(beautiful_soup_tree, makeelement):
     75      root = makeelement(beautiful_soup_tree.name,
     76                         attrib=dict(beautiful_soup_tree.attrs))
     77      _convert_children(root, beautiful_soup_tree, makeelement)
     78      return root
     79
     80 -def _convert_children(parent, beautiful_soup_tree, makeelement):
     81      SubElement = etree.SubElement
     82      et_child = None
     83      for child in beautiful_soup_tree:
     84          if isinstance(child, Tag):
     85              et_child = SubElement(parent, child.name, attrib=dict(
     86                  [(k, unescape(v)) for (k,v) in child.attrs]))
     87              _convert_children(et_child, child, makeelement)
     88          elif type(child) is NavigableString:
     89              _append_text(parent, et_child, unescape(child))
     90          else:
     91              if isinstance(child, Comment):
     92                  parent.append(etree.Comment(child))
     93              elif isinstance(child, ProcessingInstruction):
     94                  parent.append(etree.ProcessingInstruction(
     95                      *child.split(' ', 1)))
     96              else: # CData
     97                  _append_text(parent, et_child, unescape(child))
     98
     99 -def _append_text(parent, element, text):
    100      if element is None:
    101          parent.text = (parent.text or '') + text
    102      else:
    103          element.tail = (element.tail or '') + text
    104
    105
    106  # copied from ET's ElementSoup
    107
    108  from htmlentitydefs import name2codepoint
    109  import re
    110
    111  handle_entities = re.compile("&(\w+);").sub
    112
    113 -def unescape(string):
    114      if not string:
    115          return ''
    116      # work around oddities in BeautifulSoup's entity handling
    117      def unescape_entity(m):
    118          try:
    119              return unichr(name2codepoint[m.group(1)])
    120          except KeyError:
    121              return m.group(0) # use as is
    122      return handle_entities(unescape_entity, string)
    123