dwave.optimization.model.Symbol.topological_index

Symbol.topological_index()

Topological index of the node.

Return None if the model is not topologically sorted.

Examples

This example prints the indices of a two-symbol model.

>>> from dwave.optimization import Model
>>> model = Model()
>>> i = model.integer(100, lower_bound=20)
>>> sum_i = i.sum()
>>> with model.lock():
...     for symbol in model.iter_symbols():
...         print(f"Symbol {type(symbol)} is node {symbol.topological_index()}")
Symbol <class 'dwave.optimization.symbols.IntegerVariable'> is node 0
Symbol <class 'dwave.optimization.symbols.Sum'> is node 1