How does logging work?

[ebigelow]

I'm really confused on how to use the log_utils to print logged info to the console or to save it to a file. In train_composition.py I see the line log_utils.config_logging(log_file), but when I try to do this in my own script with a specific file name, nothing happens. There are no docstrings or comments in log_utils.py, and nothing about it documented anywhere as far as I can tell.