code: def extract_data(filename, num_images):
      with gzip.open(filename) as bytestream:
          bytestream.read(16)
          buf = bytestream.read(num_images * 28 * 28)
          data = np.frombuffer(buf, dtype=np.uint8).astype(np.float32)
          data = (data / 255) - 0.5
          data = data.reshape(num_images, 28, 28, 1)
          return data
  
imports: import numpy
  import os
  import gzip
  import urllib.request
label_desc: Use image node_id 1 for calling a global function with example usage: extract_data(filename, num_images) and returns: data