假設你的資料的變數名稱叫做data

#計算資料大小
total_cnt = len(data)
#8:2切割
train_cnt = int(total_cnt*0.8)
test_cnt = total_cnt - train_cnt
#創建訓練資料
trainset = data[:train_cnt]
testset = data[test_cnt:]

sklearn 的 train_test_split切割，一維/二維均可。validation再從train切一次即可。

一維:

import numpy as np
from sklearn.model_selection import train_test_split
X, y = np.arange(10), range(10)
X_train, X_test, y_train, y_test = train_test_split(
    X, y, test_size=0.33)
X_train, X_test, y_train, y_test 

二維:

import numpy as np
from sklearn.model_selection import train_test_split
X, y = np.arange(10).reshape((5, 2)), range(5)
X_train, X_test, y_train, y_test = train_test_split(
    X, y, test_size=0.33)
X_train, X_test, y_train, y_test