Join Lists

Join the three lists into one, without changing any of them.

first = [1, 2]
second = [3]
third = [4, 5]
# print the combined list

Either + twice, or unpack all three with *.

first = [1, 2]
second = [3]
third = [4, 5]
print([*first, *second, *third])

This raises TypeError. Print the numbers joined by commas.

numbers = [1, 2, 3]
print(", ".join(numbers))

join needs strings. Convert each one first.

numbers = [1, 2, 3]
print(", ".join(str(n) for n in numbers))

Build a 3 by 2 grid of zeros where changing one cell does not change the others.

grid = [[0] * 2] * 3
grid[0][0] = 99
print(grid)

Repeating a list repeats the reference. Build each row in a comprehension.

grid = [[0] * 2 for _ in range(3)]
grid[0][0] = 99
print(grid)