(self, source_key, dest_key, weight=0)
| 53 | return self.nodes[key] |
| 54 | |
| 55 | def add_edge(self, source_key, dest_key, weight=0): |
| 56 | if source_key is None or dest_key is None: |
| 57 | raise KeyError('Invalid key') |
| 58 | if source_key not in self.nodes: |
| 59 | self.add_node(source_key) |
| 60 | if dest_key not in self.nodes: |
| 61 | self.add_node(dest_key) |
| 62 | self.nodes[source_key].add_neighbor(self.nodes[dest_key], weight) |
| 63 | |
| 64 | def add_undirected_edge(self, src_key, dst_key, weight=0): |
| 65 | if src_key is None or dst_key is None: |