--- a
+++ b/sandbox/validation_splits.py
@@ -0,0 +1,35 @@
+import pathfinder
+import glob
+import random
+import utils_lung
+import utils
+
+VALIDATION_SET_SIZE = 0.2
+
+
+def read_split(path):
+    d = utils.load_pkl(path)
+    print d['valid']
+    # print d['train']
+
+
+def make_luna_validation_split():
+    luna_path = pathfinder.LUNA_DATA_PATH
+    file_list = sorted(glob.glob(luna_path + "/*.mhd"))
+    random.seed(317070)
+    all_pids = [utils_lung.extract_pid_filename(f) for f in file_list]
+    validation_pids = random.sample(all_pids, int(VALIDATION_SET_SIZE * len(file_list)))
+    train_pids = list(set(all_pids) - set(validation_pids))
+    d = {}
+    d['valid'] = validation_pids
+    d['train'] = train_pids
+    utils.save_pkl(d, pathfinder.LUNA_VALIDATION_SPLIT_PATH)
+
+
+def make_kaggle_validation_split():
+    pass
+
+
+if __name__ == '__main__':
+    make_luna_validation_split()
+    read_split(pathfinder.LUNA_VALIDATION_SPLIT_PATH)