process.py

import os

# MNIST
MNIST = 'MNIST'
def convert(imgf, labelf, outf, n):
  f = open(imgf, "rb")
  o = open(outf, "w")
  l = open(labelf, "rb")

  f.read(16)
  l.read(8)
  images = []

  for i in range(n):
    image = [ord(l.read(1))]
    for j in range(28*28):
      image.append(ord(f.read(1)))
    images.append(image)

  for image in images:
    o.write(",".join(str(pix) for pix in image)+"\n")
  f.close()
  o.close()
  l.close()

convert(os.path.join(MNIST, "train-images-idx3-ubyte"), os.path.join(MNIST, "train-labels-idx1-ubyte"), os.path.join(MNIST, "mnist_train.csv"), 60000)
convert(os.path.join(MNIST, "t10k-images-idx3-ubyte"), os.path.join(MNIST, "t10k-labels-idx1-ubyte"), os.path.join(MNIST, "mnist_test.csv"), 10000)