Changing structure of numpy array enforcing given value

Question

How can I downscale the raster data of 4 X 6 size into 2 X 3 size enforcing \'1\' to be chosen if any element with in 2*2 pixels include 1, otherwise 0

Answer 1

import numpy as np    

def toblocks(arr, nrows, ncols):
    h, w = arr.shape
    blocks = (arr.reshape(h // nrows, nrows, -1, ncols)
              .swapaxes(1, 2)
              .reshape(h // nrows, w // ncols, ncols * nrows))
    return blocks    

data = np.array([[0, 0, 1, 1, 0, 0],
                 [1, 0, 0, 1, 0, 0],
                 [1, 0, 1, 0, 0, 0],
                 [1, 1, 0, 0, 0, 0]])


blocks = toblocks(data, 2, 2)
downscaled = blocks.any(axis=-1).astype(blocks.dtype)
print(downscaled)
# [[1 1 0]
#  [1 1 0]]

---

Where the above solution comes from: A while ago, an SO question asked how to break an array into blocks. All I did was slightly modify that solution to apply any to each of the blocks.