def str_to_datetime(date_string):
    format_string = "%Y-%m-%d %H:%M:%S.%f"
    last_date_from_db = datetime.datetime.strptime(date_string, format_string) # Formating string dd-mm-yyyy hh:mm:ss.f from DataBase to class 'datetime.datetime'
    result = last_date_from_db
    return result