Initialises specified (by name suffix) loggers to generate output at the
specified logging level. If the specified named loggers do not exist,
they are created.
Parameters:
logrNameList (list of str) – List of logger names.
logLevel (int) – Log level for messages, typically
one of logging.DEBUG, logging.INFO, logging.WARN, logging.ERROR
or logging.CRITICAL.
See Logging Levels.
rootRank (int) – MPI rank of the root-logger process.