Python: Mnist Reader

mnist.py

def get_data_and_labels(images_filename, labels_filename):
    print("Opening files ...")
    images_file = open(images_filename, "rb")
    labels_file = open(labels_filename, "rb")

    try:
        print("Reading files ...")
        images_file.read(4)
        num_of_items = int.from_bytes(images_file.read(4), byteorder="big")
        num_of_rows = int.from_bytes(images_file.read(4), byteorder="big")
        num_of_colums = int.from_bytes(images_file.read(4), byteorder="big")
        labels_file.read(8)

        num_of_image_values = num_of_rows * num_of_colums
        data = [[None for x in range(num_of_image_values)]
                for y in range(num_of_items)]
        labels = []
        for item in range(num_of_items):
            print("Current image number: %7d" % item)
            for value in range(num_of_image_values):
                data[item][value] = int.from_bytes(images_file.read(1),
                                                   byteorder="big")
            labels.append(int.from_bytes(labels_file.read(1), byteorder="big"))
        return data, labels
    finally:
        images_file.close()
        labels_file.close()
        print("Files closed.")


images_filename = "location/of/images/file"
labels_filename = "location/of/labels/file"
data, labels = get_data_and_labels(images_filename, labels_filename)