Python 列表元素分组,比如 [1,2,3,...100]变成 [[1,2,3],[4,5,6]....]（列表生成式解决）

in [29]: a=[x for x in range(1,101)]

in [30]: b=[a[x:x+3] for x in range(0,100,3)]

in [31]: b
out[31]:
[[1, 2, 3],
[4, 5, 6],
[7, 8, 9],
[10, 11, 12],
[13, 14, 15],
[16, 17, 18],
[19, 20, 21],
[22, 23, 24],
[25, 26, 27],
[28, 29, 30],
[31, 32, 33],
[34, 35, 36],
[37, 38, 39],
[40, 41, 42],
[43, 44, 45],
[46, 47, 48],
[49, 50, 51],
[52, 53, 54],
[55, 56, 57],
[58, 59, 60],
[61, 62, 63],
[64, 65, 66],
[67, 68, 69],
[70, 71, 72],
[73, 74, 75],
[76, 77, 78],
[79, 80, 81],
[82, 83, 84],
[85, 86, 87],
[88, 89, 90],
[91, 92, 93],
[94, 95, 96],
[97, 98, 99],
[100]]

in [32]: a
out[32]:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67,
68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83,
84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99,
100]