import json tfs = set() with open('../Data/information/target_tf.txt') as f: for line in f: line = line.strip() lst = line.split('\t') tf = lst[1] tfs.add(tf) with open('../Data/information/target_tf_agris.txt') as f: for line in f: line = line.strip() lst = line.split('\t') tf = lst[1] tfs.add(tf) print(json.dumps(sorted(list(tfs))))