提供几个用于数据集划分的python代码

以下是几个用于数据集划分的 Python 代码示例：

1. 随机划分数据集：

from sklearn.model_selection import train_test_split

X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=.2, random_state=42)

2. 分层划分数据集：

from sklearn.model_selection import StratifiedShuffleSplit

split = StratifiedShuffleSplit(n_splits=1, test_size=.2, random_state=42)
for train_index, test_index in split.split(X, y):
    X_train = X[train_index]
    y_train = y[train_index]
    X_test = X[test_index]
    y_test = y[test_index]

3. 时间序列划分数据集：

from sklearn.model_selection import TimeSeriesSplit

tscv = TimeSeriesSplit(n_splits=5)
for train_index, test_index in tscv.split(X):
    X_train, X_test = X[train_index], X[test_index]
    y_train, y_test = y[train_index], y[test_index]

希望这些代码能够帮助你进行数据集划分。