| 24 | 24 | |
| 25 | 25 | class Graph: |
| 26 | 26 | def __init__(self, data: list | None = None): |
| 27 | | pass |
| 27 | # Edge Case: Graph data is not a list |
| 28 | if data is not None and not isinstance(data, list): |
| 29 | raise TypeError("Graph data malformed") |
| 30 | |
| 31 | # Edge Case: Empty graph data |
| 32 | if data is None: |
| 33 | data = [] |
| 34 | |
| 35 | self.nodes = [] |
| 36 | self.edges = [] |
| 37 | self.attrs = {} |
| 38 | |
| 39 | for item in data: |
| 40 | # Edge Case: Graph item is not a tuple |
| 41 | if not isinstance(item, tuple): |
| 42 | raise TypeError("Graph item malformed") |
| 43 | |
| 44 | # Edge Case: Graph item is empty tuple |
| 45 | if len(item) == 0: |
| 46 | raise TypeError("Graph item malformed") |
| 47 | |
| 48 | item_type = item[0] |
| 49 | |
| 50 | # Edge Case: Unknown item type |
| 51 | if item_type not in (NODE, EDGE, ATTR): |
| 52 | raise ValueError("Unknown item") |
| 53 | |
| 54 | # Edge Case: Attribute item with wrong number of elements |
| 55 | if item_type == ATTR: |
| 56 | if len(item) != 3: |
| 57 | raise TypeError("Graph item malformed") |
| 58 | self.attrs[item[1]] = item[2] |
| 59 | |
| 60 | # Edge Case: Node item with wrong number of elements |
| 61 | elif item_type == NODE: |
| 62 | if len(item) != 3: |
| 63 | raise TypeError("Graph item malformed") |
| 64 | self.nodes.append(Node(item[1], item[2])) |
| 65 | |
| 66 | # Edge Case: Edge item with wrong number of elements |
| 67 | elif item_type == EDGE: |
| 68 | if len(item) != 4: |
| 69 | raise TypeError("Graph item malformed") |
| 70 | self.edges.append(Edge(item[1], item[2], item[3])) |
| 71 | |
| 72 | # Handled Edge Cases: Graph data is not a list, Empty graph data, Graph item is not a tuple, |
| 73 | # Graph item is empty tuple, Unknown item type, Attribute item with wrong number of elements, |
| 74 | # Node item with wrong number of elements, Edge item with wrong number of elements |