A 2-D array is an “array or arrays”, with 2 index values:

ROOMS = 4
COMPUTERS = 5

#create array
computers = [ ["" for c in range(COMPUTERS)] for r in range(ROOMS)]
...

Nested loops are used to go through each of the index values:

...
#populate array
for room in range(ROOMS):
    for computer in range(COMPUTERS):
 
        computerID = f"r{room}c{computer}"
        computers[room][computer] = computerID

print(computers)

Printing a raw 2-D array shows the “array of arrays” structure:

[['r0c0', 'r0c1', 'r0c2', 'r0c3', 'r0c4'], ['r1c0', 
'r1c1', 'r1c2', 'r1c3', 'r1c4'], ['r2c0', 'r2c1', 'r2c2', 
'r2c3', 'r2c4'], ['r3c0', 'r3c1', 'r3c2', 'r3c3', 'r3c4']]

The printing of a 2-D array can be improved:

for room in range(ROOMS):
    for computer in range(COMPUTERS):
        print(computers[room][computer],' ',end='')
    print()

r0c0 r0c1 r0c2 r0c3 r0c4 
r1c0 r1c1 r1c2 r1c3 r1c4 
r2c0 r2c1 r2c2 r2c3 r2c4 
r3c0 r3c1 r3c2 r3c3 r3c4