matrix = [
  [ 1, 2, 3 ],
  [ 4, 5, 6 ],
  [ 7, 8, 9 ]
]
output = []
h = len(matrix)
w = len(matrix[0])

for i in range(w - 1, -1, -1):
  c = []

  for j in range(h):
    c.append(matrix[j][i])

  output.append(c)

print(output)

// Javascript implementation

const matrix = [
  [ 1, 2, 3 ],
  [ 4, 5, 6 ],
  [ 7, 8, 9 ]
];
const output = [];
const h = matrix.length;
const w = matrix[0].length;

for (let i = w - 1; i >= 0 ; i--) {
  let c = [];

  for (let j = 0; j < h; j++) {
    c.push(matrix[j][i]);
  }

  output.push(c);
}

console.log(output);