Alcides Fonseca

While preparing geneticengine to participate in the SRBench 2024 run, I was getting None out of a constructor:

def PredictorWrapper(BaseEstimator):
    def __init__(self, ind: tuple[str, str]):
        self.ind = ind


    def predict(self, X):
        _, data = self.prepare_inputs(X)
        return forward_dataset(self.ind0, data)

    def to_sympy(self):
        return self.ind1


	
def mk_estimator(x):
    print(f“x={x}”)
    p = PredictorWrapper(x)
    print(f“p={p}”)
    return p

Outputting:

x=('np.log(np.power(dataset[:,1], 10.0))', 'log((x1 ** 10.0))')
p=None

Have you found the bug? It took me probably around 1 hour, mainly because I trusted myself too much (and there many other things going on in the code). If you still haven’t found the bug, check the first 3 characters of the code snippet. A function with only other functions inside returns None.