numpy.union1d() function in Python

• Last Updated : 12 Jun, 2020

`numpy.union1d()` function find the union of two arrays and return the unique, sorted array of values that are in either of the two input arrays.

Syntax : numpy.union1d(arr1, arr2)

Parameters :
arr1, arr2 : [array_like] Input arrays.

Return : [ndarray] Unique, sorted union of the input arrays.

Code #1 :

 `# Python program explaining``# numpy.union1d() function``   ` `# importing numpy as geek ``import` `numpy as geek ``  ` `arr1 ``=` `[``-``1``, ``0``, ``1``]``arr2 ``=` `[``-``2``, ``0``, ``2``]``  ` `gfg ``=` `geek.union1d(arr1, arr2)``  ` `print` `(gfg)`

Output :

```[-2 -1  0  1  2]
```

Code #2 :

 `# Python program explaining``# numpy.union1d() function``   ` `# importing numpy as geek ``import` `numpy as geek ``  ` `arr1 ``=` `[``-``3``, ``-``2``, ``-``1``, ``0``, ``1``, ``2``, ``3``]``arr2 ``=` `[``-``5``, ``-``4``, ``-``3``, ``0``, ``3``, ``4``, ``5``]``  ` `gfg ``=` `geek.union1d(arr1, arr2)``  ` `print` `(gfg)`

Output :

```[-5 -4 -3 -2 -1  0  1  2  3  4  5]
```

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