import sys
from pymongo import MongoClient
from pymongo.errors import ConnectionFailure


def main():
    """连接 MongoDB数据库"""
    try:
        client = MongoClient(host="localhost", port=27017)
        print("mongoDB成功连接")
    except ConnectionFailure:
        sys.stderr.write("连接失败了")


if __name__ == '__main__':
    main()