module types_linq.more.more_error

class DirectedGraphNotAcyclicError

from types_linq.more import DirectedGraphNotAcyclicError

Exception raised when a cycle exists in a graph.

Revisions

v1.2.1: New.

Bases

• InvalidOperationError

Members

instanceproperty cycle

Returns

Tuple[object, object]

The two elements (A, B) in this tuple are part of a cycle. There exists an edge from A to B, and a path from B back to A. A and B may be identical.

Example

>>> adj = { 5: [2, 0], 4: [0, 1], 2: [3], 3: [1, 5] }
>>> try:
>>>     MoreEnumerable([5, 4]).traverse_topological(lambda x: adj.get(x, [])) \
>>>         .consume()
>>> except DirectedGraphNotAcyclicError as e:
>>>     print(e.cycle)
(3, 5)  # 3 -> 5 -> 2 -> 3