numpy.random.shuffle

random.shuffle(x)

Modify a sequence in-place by shuffling its contents.

This function only shuffles the array along the first axis of a multi-dimensional array. The order of sub-arrays is changed but their contents remains the same.

Note

New code should use the shuffle method of a Generator instance instead; please see the Quick Start.

Parameters:

xndarray or MutableSequence

The array, list or mutable sequence to be shuffled.

Returns:

None

See also

random.Generator.shuffle

which should be used for new code.

Examples

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

Multi-dimensional arrays are only shuffled along the first axis:

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