import pymongo
myclient = pymongo.MongoClient("mongodb://user:password@localhost:37017,localhost:37018/test?authSource=admin&connectTimeoutMS=9000&readConcernLevel=majority&readPreference=secondaryPreferred&retryReads=true&minPoolSize=100&maxPoolSize=100&socketKeepAlive=true")
mydb = myclient["dbtest"]
mycol = mydb["colltest"]

#print(myclient);

doc={ 'a': 1,'b': 2}

#print(myclient.admin.command('currentOp'))
print(myclient.admin.command('ismaster'))
mycol.insert(doc);
{
    return foo;
}

$ python3 script.py
Traceback (most recent call last):
  File "script.py", line 11, in <module>
    print(myclient.admin.command('ismaster'))
  File "/usr/local/lib64/python3.6/site-packages/pymongo/database.py", line 733, in command
    codec_options, session=session, **kwargs)
  File "/usr/local/lib64/python3.6/site-packages/pymongo/database.py", line 630, in _command
    client=self.__client)
  File "/usr/local/lib64/python3.6/site-packages/pymongo/pool.py", line 613, in command
    user_fields=user_fields)
  File "/usr/local/lib64/python3.6/site-packages/pymongo/network.py", line 167, in command
    parse_write_concern_error=parse_write_concern_error)
  File "/usr/local/lib64/python3.6/site-packages/pymongo/helpers.py", line 159, in _check_command_response
    raise OperationFailure(msg % errmsg, code, response)
pymongo.errors.OperationFailure: Cache Reader No keys found for HMAC that is valid for time: { ts: Timestamp(1630774279, 1) } with id: 7004119824641032208