x是輸入的矩陣，print(k)會印出2*2的矩陣呦 :D

還蠻有趣的對吧？可以參考more_itertools.grouper了解詳細原理

https://myapollo.com.tw/zh-tw/python-itertools-more-itertools/#grouper

https://more-itertools.readthedocs.io/en/stable/_modules/more_itertools/recipes.html#grouper

https://docs.python.org/3/library/itertools.html#:~:text=def%20grouper(iterable%2C%20n%2C%20fillvalue%3DNone)%3A%0A%20%20%20%20%22Collect%20data%20into%20fixed-length%20chunks%20or%20blocks%22%0A%20%20%20%20%23%20grouper(%27ABCDEFG%27%2C%203%2C%20%27x%27)%20--%3E%20ABC%20DEF%20Gxx%22%0A%20%20%20%20args%20%3D%20%5Biter(iterable)%5D%20*%20n%0A%20%20%20%20return%20zip_longest(*args%2C%20fillvalue%3Dfillvalue)