首先是参考网站：
- http://yann.lecun.com/exdb/mnist/
- https://docs.python.org/zh-cn/3.8/library/struct.html
- https://docs.python.org/zh-cn/3.8/tutorial/inputoutput.html#tut-files
- https://blog.csdn.net/simple_the_best/article/details/75267863
- https://numpy.org/doc/stable/reference/generated/numpy.fromfile.html
然后就是具体咋写的
from typing import Tuple
import pandas as pd
import numpy as np
import sys
import struct
def read_label_in_idx1_ubyte(path: str) -> Tuple[int, int, pd.DataFrame]:
file = open(path, mode="rb")
magic_number, count = struct.unpack(">ii", file.read(8))
labels = np.fromfile(file=file, dtype=np.uint8)
labels = pd.DataFrame(labels)
return magic_number, count, labels
def read_image_in_idx3_ubyte(path: str) -> Tuple[int, int, int, int, pd.DataFrame]:
file = open(path, mode="rb")
magic_number, count, rows, columns = struct.unpack(">iiii", file.read(16))
images: np.array = np.fromfile(file=file, dtype=np.uint8)
images = images.reshape(count, (rows*columns))
images = pd.DataFrame(images)
return magic_number,count,rows,columns,images
labels = read_label_in_idx1_ubyte(
"MNIST/train-labels-idx1-ubyte/train-labels.idx1-ubyte")[-1]
image = read_image_in_idx3_ubyte(
"MNIST/train-images-idx3-ubyte/train-images.idx3-ubyte")[-1]
说点坑，首先这个必须用二进制流打开，然后，是大端模式。