там в доке написано ещё:
One can also pass a dict mapping module names to minimum required level.
In such case, each log record will search for it’s closest parent in the dict and use the associated level as the filter. The dict values can be int severity, str level name or True and False to respectively authorize and discard all module logs unconditionally. In order to set a default level, the "" module name should be used as it is the parent of all modules (it does not suppress global level threshold, though).