_lxml.py 文件源码

def start(self, name, attrs, nsmap={}):
        # Make sure attrs is a mutable dict--lxml may send an immutable dictproxy.
        attrs = dict(attrs)

        nsprefix = None
        # Invert each namespace map as it comes in.
        if len(nsmap) == 0 and self.nsmaps != None:
            # There are no new namespaces for this tag, but namespaces
            # are in play, so we need a separate tag stack to know
            # when they end.
            self.nsmaps.append(None)
        elif len(nsmap) > 0:
            # A new namespace mapping has come into play.
            if self.nsmaps is None:
                self.nsmaps = []
            inverted_nsmap = dict((value, key) for key, value in nsmap.items())
            self.nsmaps.append(inverted_nsmap)
            # Also treat the namespace mapping as a set of attributes on the
            # tag, so we can recreate it later.
            attrs = attrs.copy()
            for prefix, namespace in nsmap.items():
                attribute = NamespacedAttribute(
                    "xmlns", prefix, "http://www.w3.org/2000/xmlns/")
                attrs[attribute] = namespace

        if self.nsmaps is not None and len(self.nsmaps) > 0:
            # Namespaces are in play. Find any attributes that came in
            # from lxml with namespaces attached to their names, and
            # turn then into NamespacedAttribute objects.
            new_attrs = {}
            for attr, value in attrs.items():
                namespace, attr = self._getNsTag(attr)
                if namespace is None:
                    new_attrs[attr] = value
                else:
                    nsprefix = self._prefix_for_namespace(namespace)
                    attr = NamespacedAttribute(nsprefix, attr, namespace)
                    new_attrs[attr] = value
            attrs = new_attrs

        namespace, name = self._getNsTag(name)
        nsprefix = self._prefix_for_namespace(namespace)
        self.soup.handle_starttag(name, namespace, nsprefix, attrs)