numpy.union1d¶
- numpy.union1d(ar1, ar2)[source]¶
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])
To find the union of more than two arrays, use functools.reduce:
>>> from functools import reduce >>> reduce(np.union1d, ([1, 3, 4, 3], [3, 1, 2, 1], [6, 3, 4, 2])) array([1, 2, 3, 4, 6])