python
导入必要的库
from sklearn.model_selection import train_test_split
from sklearn.linear_model import LinearRegression
from sklearn.metrics import mean_squared_error
import numpy as np
假设我们有一些数据集
X = np.array([[1], [2], [3], [4], [5]]) 特征
y = np.array([1, 2, 3, 4, 5]) 目标变量
将数据集分为训练集和测试集
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)