join_dataset.py

import os
import json

json_files = [];

for file in os.listdir():
    if file.endswith('.json'):
        json_files.append(file)

result = list()

for f1 in json_files:
    with open(f1, 'r') as infile:
        result.extend(json.load(infile))

with open('join_dataset.json', 'w') as output_file:
    json.dump(result, output_file)