(self)
The node immediately following the invocant in their parent's children
        list. If the invocant does not have a next sibling, it is None
The node immediately following the invocant in their parent's children
        list. If the invocant does not have a next sibling, it is None
The node immediately following the invocant in their parent s children list . If the invocant does not have a next sibling it is None
def next_sibling(self):
        """
        The node immediately following the invocant in their parent's children
        list. If the invocant does not have a next sibling, it is None
        """
        if self.parent is None:
            return None

        # Can't use index(); we need to test by identity
        for i, child in enumerate(self.parent.children):
            if child is self:
                try:
                    return self.parent.children[i+1]
                except IndexError:
                    return None
def next_sibling ( self ) : if self . parent is None : return None # Can't use index(); we need to test by identity for i , child in enumerate ( self . parent . children ) : if child is self : try : return self . parent . children [ i + 1 ] except IndexError : return None