ValueError: LabelBinarizer 'y' should be 1d

ValueError: LabelBinarizer y 1d

$ python -c "from sklearn.preprocessing import LabelBinarizer; import numpy as np; LabelBinarizer().fit(np.array([[0,1],[1,0]]))"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ValueError: y should be a 1d array

Why this happens

Provided labels are multi-dimensional.

Fix

Flatten to 1D labels.

Wrong code

from sklearn.preprocessing import LabelBinarizer
import numpy as np
LabelBinarizer().fit(np.array([[0,1],[1,0]]))

Fixed code

from sklearn.preprocessing import LabelBinarizer
import numpy as np
LabelBinarizer().fit(np.array([0,1,0,1]))