numpy.nonzero — NumPy v1.13 Manual

numpy.nonzero¶ numpy.nonzero(a)[source]¶ Return the indices of the elements that are non-zero. Returns a tuple of arrays, one for each dimension of a, containing the indices of the non-zero elements in that dimension. The values in a are always tested and returned in row-major, C-style order. The corresponding non-zero values can be obtained with:

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