Set the logging level.
The verbosity of messages to print. If a str, it can be either DEBUG, INFO, WARNING, ERROR, or CRITICAL. Note that these are for convenience and are equivalent to passing in logging.DEBUG, etc. For bool, True is the same as ‘INFO’, False is the same as ‘WARNING’. If None, the environment variable MNE_LOGGING_LEVEL is read, and if it doesn’t exist, defaults to INFO.
If True, return the old verbosity level.
If int, enable (>=1) or disable (0) the printing of stack frame information using formatting. Default (None) does not change the formatting. This can add overhead so is meant only for debugging.
The old level. Only returned if
return_old_level is True.