Method remove_edge

networkx/algorithms/planarity.py:1199–1238

Remove the edge between u and v. Parameters ---------- u, v : nodes Remove the half-edges (u, v) and (v, u) and update the edge ordering around the removed edge. Raises ------ NetworkXError If there is not an edge between u an

(self, u, v)

        self.add_half_edge(start_node, end_node, ccw=reference_neighbor)

    def remove_edge(self, u, v):
        """Remove the edge between u and v.

        Parameters
        ----------
        u, v : nodes
        Remove the half-edges (u, v) and (v, u) and update the
        edge ordering around the removed edge.

        Raises
        ------
        NetworkXError
        If there is not an edge between u and v.

        See Also
        --------
        remove_edges_from : remove a collection of edges
        """
        try:
            succs_u = self._succ[u]
            succs_v = self._succ[v]
            uv_cw = succs_u[v]["cw"]
            uv_ccw = succs_u[v]["ccw"]
            vu_cw = succs_v[u]["cw"]
            vu_ccw = succs_v[u]["ccw"]
            del succs_u[v]
            del self._pred[v][u]
            del succs_v[u]
            del self._pred[u][v]
            if v != uv_cw:
                succs_u[uv_cw]["ccw"] = uv_ccw
                succs_u[uv_ccw]["cw"] = uv_cw
            if u != vu_cw:
                succs_v[vu_cw]["ccw"] = vu_ccw
                succs_v[vu_ccw]["cw"] = vu_cw
        except KeyError as err:
            raise nx.NetworkXError(
                f"The edge {u}-{v} is not in the planar embedding."
            ) from err
        nx._clear_cache(self)

    def remove_edges_from(self, ebunch):
        """Remove all edges specified in ebunch.