def _match(self, pred):
        """
        Helper function to determine if this node matches the given predicate.
        """
        if not pred:
            return True
        # Strip off the [ and ]
        pred = pred[1:-1]
        if pred.startswith('@'):
            # An attribute predicate checks the existence (and optionally value) of an attribute on this tag.
            pred = pred[1:]
            if '=' in pred:
                attr, value = pred.split('=', 1)
                if value[0] in ('"', "'"):
                    value = value[1:]
                if value[-1] in ('"', "'"):
                    value = value[:-1]
                return self.attrs.get(attr) == value
            else:
                return pred in self.attrs
        elif num_re.match(pred):
            # An index predicate checks whether we are the n-th child of our parent (0-based).
            index = int(pred)
            if index < 0:
                if self.parent:
                    # For negative indexes, count from the end of the list.
                    return self.index == (len(self.parent._children) + index)
                else:
                    # If we're the root node, the only index we could be is 0.
                    return index == 0
            else:
                return index == self.index
        else:
            if '=' in pred:
                tag, value = pred.split('=', 1)
                if value[0] in ('"', "'"):
                    value = value[1:]
                if value[-1] in ('"', "'"):
                    value = value[:-1]
                for c in self._children:
                    if c.tagname == tag and c.data == value:
                        return True
            else:
                # A plain [tag] predicate means we match if we have a child with tagname "tag".
                for c in self._children:
                    if c.tagname == pred:
                        return True
        return False
def _match(self, pred):
        """
        Helper function to determine if this node matches the given predicate.
        """
        if not pred:
            return True
        # Strip off the [ and ]
        pred = pred[1:-1]
        if pred.startswith('@'):
            # An attribute predicate checks the existence (and optionally value) of an attribute on this tag.
            pred = pred[1:]
            if '=' in pred:
                attr, value = pred.split('=', 1)
                if value[0] in ('"', "'"):
                    value = value[1:]
                if value[-1] in ('"', "'"):
                    value = value[:-1]
                return self.attrs.get(attr) == value
            else:
                return pred in self.attrs
        elif num_re.match(pred):
            # An index predicate checks whether we are the n-th child of our parent (0-based).
            index = int(pred)
            if index < 0:
                if self.parent:
                    # For negative indexes, count from the end of the list.
                    return self.index == (len(self.parent._children) + index)
                else:
                    # If we're the root node, the only index we could be is 0.
                    return index == 0
            else:
                return index == self.index
        else:
            if '=' in pred:
                tag, value = pred.split('=', 1)
                if value[0] in ('"', "'"):
                    value = value[1:]
                if value[-1] in ('"', "'"):
                    value = value[:-1]
                for c in self._children:
                    if c.tagname == tag and c.data == value:
                        return True
            else:
                # A plain [tag] predicate means we match if we have a child with tagname "tag".
                for c in self._children:
                    if c.tagname == pred:
                        return True
        return False
def _match ( self , pred ) : if not pred : return True # Strip off the [ and ] pred = pred [ 1 : - 1 ] if pred . startswith ( '@' ) : # An attribute predicate checks the existence (and optionally value) of an attribute on this tag. pred = pred [ 1 : ] if '=' in pred : attr , value = pred . split ( '=' , 1 ) if value [ 0 ] in ( '"' , "'" ) : value = value [ 1 : ] if value [ - 1 ] in ( '"' , "'" ) : value = value [ : - 1 ] return self . attrs . get ( attr ) == value else : return pred in self . attrs elif num_re . match ( pred ) : # An index predicate checks whether we are the n-th child of our parent (0-based). index = int ( pred ) if index < 0 : if self . parent : # For negative indexes, count from the end of the list. return self . index == ( len ( self . parent . _children ) + index ) else : # If we're the root node, the only index we could be is 0. return index == 0 else : return index == self . index else : if '=' in pred : tag , value = pred . split ( '=' , 1 ) if value [ 0 ] in ( '"' , "'" ) : value = value [ 1 : ] if value [ - 1 ] in ( '"' , "'" ) : value = value [ : - 1 ] for c in self . _children : if c . tagname == tag and c . data == value : return True else : # A plain [tag] predicate means we match if we have a child with tagname "tag". for c in self . _children : if c . tagname == pred : return True return False
Helper function to determine if this node matches the given predicate.
Helper function to determine if this node matches the given predicate .