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I'm aware that there are other questions with the same name, but they're all about indexing and I'm getting this error when trying to invoke func(r_curr). I've already checked and func is not NoneType after assignment, it is <function <lambda> at 0x000001BB1E91E510>.

def eval_symb_reg(individual, points):
      global X
      global y
      global size
      func = toolbox.compile(expr=individual)
      predict = []
      for i in range(X.shape[0]):
        total = 0
        for j in range(size):
          r_curr = X[i][j*size:(j+1)*size]
          result = func(r_curr)
          total += result[0]
        predict.append(total)
      error = np.sum((np.array(predict) - y) ** 2)
      return [1 / (error / X.shape[0])]

Stack trace:

Traceback (most recent call last):
  File "symbreg.py", line 298, in <module>
    main()
  File "symbreg.py", line 265, in main
    halloffame=hof, verbose=True)
  File "C:\Users\<myuser>\AppData\Local\Programs\Python\Python36\lib\site-packages\deap\algorithms.py", line 151, in eaSimple
    for ind, fit in zip(invalid_ind, fitnesses):
  File "symbreg.py", line 198, in eval_symb_reg
    result = func(r_curr)
  File "<string>", line 1, in <lambda>
TypeError: 'NoneType' object is not subscriptable
Andrew
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  • `func` doesn't return anything (or it explicitly is returning `None`), so writing `result[0]` means nothing. – Kraigolas Mar 15 '21 at 04:07
  • @Kraigolas I don't understand - the error occurs before the line with result[0], so this would be unrelated? – Andrew Mar 15 '21 at 18:32

0 Answers0