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# numpy.union1d

`numpy.``union1d`(ar1, ar2)

  Find the union of two arrays.

  Return the unique, sorted array of values that are in either of the two input arrays.

  Parameters : | ar1, ar2 : array_like Input arrays. They are flattened if they are not already 1D.
  Returns : | union1d : ndarray Unique, sorted union of the input arrays.

  See also

  `numpy.lib.arraysetops`
    Module with a number of other functions for performing set operations on arrays.

  Examples

      >>> np.union1d([-1, 0, 1], [-2, 0, 2])
      array([-2, -1,  0,  1,  2])