Python 2D Lists Quiz

How do you access the element in the second row and third column of a 2D list `matrix`?

• `matrix[1][2]`

• `matrix[2][3]`

• `matrix[2][1]`

• `matrix[3][2]`

How can you modify the value of the first element in the first row of a 2D list `matrix` to 5?

• `matrix[0][0] = 5`

• `matrix[1][1] = 5`

• `matrix[0] = 5`

• `matrix = 5`

Which of the following is the correct way to iterate over each element in a 2D list `matrix` using nested loops?

• `for i in matrix:

  for j in i:

  print(j)`

• `for i in range(len(matrix)):

  for j in range(len(matrix[i])):

  print(matrix[i][j])`

• `for i in matrix:

  print(i)`

• `for i in range(matrix):

  for j in range(i):

  print(matrix[i][j])`

What will be the output of the following code snippet if `matrix = [[1, 2], [3, 4]]`? ```python print(matrix[1][1]) ```

• `1`

• `2`

• `3`

• `4`

Which of the following is a valid 2D list in Python?

• `[[1, 2, 3], [4, 5], [6]]`

• `[[1, 2], 3, [4, 5]]`

• `[[1], [2, 3], 4]`

• [[1] [2] [3]]

How can you add a new row `[5, 6, 7]` to an existing 2D list `matrix`?

• `matrix.append(5, 6, 7)`

• `matrix.append([5, 6, 7])`

• `matrix += [5, 6, 7]`

• `matrix.insert(len(matrix), [5, 6, 7])`

What error is raised when trying to access an element in a 2D list with an index that is out of range?

• `IndexError`

• `KeyError`

• `TypeError`

• `ValueError`

How do you remove the last row from a 2D list `matrix`?

• matrix[-1].delete()

• `matrix.pop()`

• `matrix.remove(-1)`

• Both A) and B) are correct

What is the result of the following code snippet? ```python matrix = [[1, 2], [3, 4]] for row in matrix: for item in row: print(item, end=' ') ```

• `1 2 3 4`

• `[[1, 2], [3, 4]]`

• `1 2\n3 4`

• `1234`

What is the correct way to find the number of rows in a 2D list `matrix`?

• `len(matrix[0])`

• `len(matrix)`

• `len(matrix.columns)`

• `len(matrix.rows)`