Python | Creating a 3D List

A 3-D List means that we need to make a list that has three parameters to it, i.e., (a x b x c), just like a 3 D array in other languages. In this program we will try to form a 3-D List with its content as “#”. Lets look at these following examples:

Input : 
3 x 3 x 3
Output :
[[['#', '#', '#'], ['#', '#', '#'], ['#', '#', '#']],
 [['#', '#', '#'], ['#', '#', '#'], ['#', '#', '#']],
 [['#', '#', '#'], ['#', '#', '#'], ['#', '#', '#']]]

Input :
5 x 3 x 2
Output :
[[['#', '#', '#', '#', '#'],
  ['#', '#', '#', '#', '#'],
  ['#', '#', '#', '#', '#']],
 [['#', '#', '#', '#', '#'],
  ['#', '#', '#', '#', '#'],
  ['#', '#', '#', '#', '#']]]

# Python program to print 3D list
# importing pretty printed
import pprint

def ThreeD(a, b, c):
    lst = [[ ['#' for col in range(a)] for col in range(b)] for row in range(c)]
    return lst

# Driver Code
col1 = 5
col2 = 3
row = 2
# used the pretty printed function
pprint.pprint(ThreeD(col1, col2, row))

Output:

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

Refer pprint() to get more insight into this topic.

Now let’s suppose we need to merge two 3D lists into one.

# Python program to merge two 3D list into one
# importing pretty printed
import pprint

def ThreeD(a, b, c):
    lst1 = [[ ['1' for col in range(a)] for col in range(b)] for row in range(c)]
    lst2= [[ ['2' for col in range(a)] for col in range(b)] for row in range(c)]
    # Merging using "+" operator
    lst = lst1+lst2
    return lst

# Driver Code
col1 = 3
col2 = 3
row = 3

# used the pretty printed function
pprint.pprint(ThreeD(col1, col2, row))

Output:

[[['1', '1', '1'], ['1', '1', '1'], ['1', '1', '1']],
 [['1', '1', '1'], ['1', '1', '1'], ['1', '1', '1']],
 [['1', '1', '1'], ['1', '1', '1'], ['1', '1', '1']],
 [['2', '2', '2'], ['2', '2', '2'], ['2', '2', '2']],
 [['2', '2', '2'], ['2', '2', '2'], ['2', '2', '2']],
 [['2', '2', '2'], ['2', '2', '2'], ['2', '2', '2']]]