Split data set to test and validation set (after split data set to training and test set)

+# -*- coding: utf-8 -*-
+"""split_to_test_validation.ipynb
+
+Automatically generated by Colaboratory.
+
+Original file is located at
+    https://colab.research.google.com/drive/16Rn0IDJTE6vJMOZtafDAI19AvGD9eK4C
+"""
+
+import pandas as pd
+from sklearn.model_selection import train_test_split
+
+dataset_url = '/content/drive/MyDrive/2d-slice-set-networks-for-brain-age-master/data/test0609.csv'
+data = pd.read_csv(dataset_url)
+print(data.head())
+
+y = data.age_at_scan
+X = data
+
+X_train, X_test, y_train, y_test = train_test_split(X, y,test_size=0.3333)
+print("\nX_train:\n")
+print(X_train.head())
+print(X_train.shape)
+X_train.to_csv('/content/drive/MyDrive/2d-slice-set-networks-for-brain-age-master/data/test0609.csv', index=False)
+
+print("\nX_test:\n")
+print(X_test.head())
+print(X_test.shape)
+X_test.to_csv('/content/drive/MyDrive/2d-slice-set-networks-for-brain-age-master/data/valid0609.csv', index=False)
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