mnist_training.py 文件源码

def loadData(src, cimg):
    gzfname, h = urlretrieve(src, './delete.me')
    try:
        with gzip.open(gzfname) as gz:
            n = struct.unpack('I', gz.read(4))
            if n[0] != 0x3080000:
                raise Exception('Invalid file: unexpected magic number.')
            n = struct.unpack('>I', gz.read(4))[0]
            if n != cimg:
                raise Exception('Invalid file: expected {0} entries.'.format(cimg))
            crow = struct.unpack('>I', gz.read(4))[0]
            ccol = struct.unpack('>I', gz.read(4))[0]
            if crow != 28 or ccol != 28:
                raise Exception('Invalid file: expected 28 rows/cols per image.')
            res = np.fromstring(gz.read(cimg * crow * ccol), dtype=np.uint8)
    finally:
        os.remove(gzfname)
    return res.reshape((cimg, crow * ccol))