def get_time_stamp(ct):

    local_time = time.localtime(ct)

    data_head = time.strftime("%Y-%m-%d %H:%M:%S", local_time)
　　 data_secs = (ct - int(ct)) *

    time_stamp = "%s:%03d" % (data_head, data_secs)

    return time_stamp

print(get_time_stamp(1546244983.3656037))

-- :::

import datetime

print(datetime.datetime.now())

print(datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S:%f'))

print(datetime.datetime.now().strftime('%Y%m%d%H%M%S%f'))