How to set verbosity/logger levels programmatically?

edit

For anybody stumbling upon this page, if you just want to set verbosity of packages as soon as they are launched by launchfiles, the easiest way is:

1. to export ROSCONSOLE_CONFIG_FILE="/path/to/my/config/rosconsole.config"
2. edit, for example with vi /path/to/my/config/rosconsole.config adding these lines:

log4j.logger.ros=INFO

log4j.logger.ros.roscpp.superdebug=WARN

log4j.logger.ros.my_package_name=DEBUG

3. launch your launchfile in the same shell.

The package name must be the one who corresponds to <node pkg="my_package_name" ...> line in the launchfile.

I do this quite often when writing new nodes in C++. Usually what I do is place the following little snippet right after my call to ros::init

log4cxx::LoggerPtr my_logger =
           log4cxx::Logger::getLogger(ROSCONSOLE_DEFAULT_NAME);
my_logger->setLevel(
           ros::console::g_level_lookup[ros::console::levels::Debug]);

This will set the node's log level to Debug. Then I comment it out after the node is sufficiently developed. I have never really looked into doing this in rospy or roslisp, but would also be interested in figuring out how.

EDIT

I just realized that this is quite easy to do with rospy as well. As documented here, you can simply pass the log_level argument to a call to rospy.init_node() e.g.

rospy.init_node('my_node', log_level=rospy.DEBUG)