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pythonlistrandomshuffle

Shuffling a list of objects

How do I shuffle a list of objects? I tried random.shuffle:

import random

b = [object(), object()]

print(random.shuffle(b))

But it outputs:

None
Solution

  • random.shuffle should work. Here's an example, where the objects are lists:

    from random import shuffle

x = [[i] for i in range(10)]
shuffle(x)
print(x)

# print(x)  gives  [[9], [2], [7], [0], [4], [5], [3], [1], [8], [6]]

    Note that shuffle works in place, and returns None.

    More generally in Python, mutable objects can be passed into functions, and when a function mutates those objects, the standard is to return None (rather than, say, the mutated object).