numpy.random.Generator.shuffle

method

random.Generator.shuffle(x, axis=0)

Modify an array or sequence in-place by shuffling its contents.

The order of sub-arrays is changed but their contents remains the same.

Parameters:

xndarray or MutableSequence

The array, list or mutable sequence to be shuffled.

axisint, optional

The axis which x is shuffled along. Default is 0. It is only supported on ndarray objects.

Returns:

None

See also

permuted

permutation

Notes

An important distinction between methods shuffle and permuted is how they both treat the axis parameter which can be found at Handling the axis parameter.

Examples

>>> rng = np.random.default_rng()
>>> arr = np.arange(10)
>>> arr
array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
>>> rng.shuffle(arr)
>>> arr
array([2, 0, 7, 5, 1, 4, 8, 9, 3, 6]) # random

>>> arr = np.arange(9).reshape((3, 3))
>>> arr
array([[0, 1, 2],
       [3, 4, 5],
       [6, 7, 8]])
>>> rng.shuffle(arr)
>>> arr
array([[3, 4, 5], # random
       [6, 7, 8],
       [0, 1, 2]])

>>> arr = np.arange(9).reshape((3, 3))
>>> arr
array([[0, 1, 2],
       [3, 4, 5],
       [6, 7, 8]])
>>> rng.shuffle(arr, axis=1)
>>> arr
array([[2, 0, 1], # random
       [5, 3, 4],
       [8, 6, 7]])