CODEWITHSUNDEEP
pythonmultidimensional-arraynested-lists
J. B.
J. B.

Reputation: 165

How can I create a 3D array made of more than one object in Python?

I know that if I wanted to create a 3D array in Python, I could do this:

[[['#' for i in range(3)] for j in range(3)] for k in range(3)]

That said, what if I wanted to include another symbol in the 3D array? For example, what if I wanted to alternate between '#' and '-' in the array? Or what if I wanted two '#''s in a row, followed by a '-'. How could I write that? Thanks for your time.

Upvotes: 2

Views: 151

Answers (3)

U13-Forward
U13-Forward

Reputation: 71610

Try with itertools.cycle:

import itertools
it = itertools.cycle(['#', '-', '#'])
print([[[next(it) for i in range(3)] for j in range(3)] for k in range(3)])

Output:

[[['#', '-', '#'], ['#', '-', '#'], ['#', '-', '#']], [['#', '-', '#'], ['#', '-', '#'], ['#', '-', '#']], [['#', '-', '#'], ['#', '-', '#'], ['#', '-', '#']]]

Upvotes: 2

costaparas
costaparas

Reputation: 5237

Check the value of i, and insert # if its < 2; otherwise put -:

[[['#' if i < 2 else '-' for i in range(3)] for j in range(3)] for k in range(3)]

To alternate, just use modulus:

[[['#' if i % 2 == 0 else '-' for i in range(3)] for j in range(3)] for k in range(3)]

Upvotes: 1

imraklr
imraklr

Reputation: 324

Try this:

>>> [[['#' if i%2==0 else '-' for i in range(3)] for j in range(3)] for k in range(3)]
[[['#', '-', '#'], ['#', '-', '#'], ['#', '-', '#']], [['#', '-', '#'], ['#', '-', '#'], ['#', '-', '#']], [['#', '-', '#'], ['#', '-', '#'], ['#', '-', '#']]]

Upvotes: 1

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