param_talker.py
Go to the documentation of this file.
00001 #!/usr/bin/env python
00002 # Software License Agreement (BSD License)
00003 #
00004 # Copyright (c) 2008, Willow Garage, Inc.
00005 # All rights reserved.
00006 #
00007 # Redistribution and use in source and binary forms, with or without
00008 # modification, are permitted provided that the following conditions
00009 # are met:
00010 #
00011 #  * Redistributions of source code must retain the above copyright
00012 #    notice, this list of conditions and the following disclaimer.
00013 #  * Redistributions in binary form must reproduce the above
00014 #    copyright notice, this list of conditions and the following
00015 #    disclaimer in the documentation and/or other materials provided
00016 #    with the distribution.
00017 #  * Neither the name of Willow Garage, Inc. nor the names of its
00018 #    contributors may be used to endorse or promote products derived
00019 #    from this software without specific prior written permission.
00020 #
00021 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00022 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00023 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00024 # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
00025 # COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00026 # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00027 # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
00028 # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
00029 # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00030 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
00031 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00032 # POSSIBILITY OF SUCH DAMAGE.
00033 #
00034 # Revision $Id: listener.py 5263 2009-07-17 23:30:38Z sfkwc $
00035 
00036 ## Simple talker demo that listens to std_msgs/Strings published 
00037 ## to the 'chatter' topic
00038 
00039 PKG = 'rospy_tutorials' # this package name
00040 import roslib; roslib.load_manifest(PKG)
00041 
00042 import rospy
00043 from std_msgs.msg import String
00044 
00045 def param_talker():
00046     rospy.init_node('param_talker')
00047 
00048     # Fetch values from the Parameter Server. In this example, we fetch
00049     # parameters from three different namespaces:
00050     #
00051     # 1) global (/global_example)
00052     # 2) parent (/foo/utterance)
00053     # 3) private (/foo/param_talker/topic_name)
00054 
00055     # fetch a /global parameter
00056     global_example = rospy.get_param("/global_example")
00057     rospy.loginfo("%s is %s", rospy.resolve_name('/global_example'), global_example)
00058     
00059     # fetch the utterance parameter from our parent namespace
00060     utterance = rospy.get_param('utterance')
00061     rospy.loginfo("%s is %s", rospy.resolve_name('utterance'), utterance)
00062     
00063     # fetch topic_name from the ~private namespace
00064     topic_name = rospy.get_param('~topic_name')
00065     rospy.loginfo("%s is %s", rospy.resolve_name('~topic_name'), topic_name)
00066 
00067     # fetch a parameter, using 'default_value' if it doesn't exist
00068     default_param = rospy.get_param('default_param', 'default_value')
00069     rospy.loginfo('%s is %s', rospy.resolve_name('default_param'), default_param)
00070     
00071     # fetch a group (dictionary) of parameters
00072     gains = rospy.get_param('gains')
00073     p, i, d = gains['P'], gains['I'], gains['D']
00074     rospy.loginfo("gains are %s, %s, %s", p, i, d)    
00075 
00076     # set some parameters
00077     rospy.loginfo('setting parameters...')
00078     rospy.set_param('list_of_floats', [1., 2., 3., 4.])
00079     rospy.set_param('bool_True', True)
00080     rospy.set_param('~private_bar', 1+2)
00081     rospy.set_param('to_delete', 'baz')
00082     rospy.loginfo('...parameters have been set')
00083 
00084     # delete a parameter
00085     if rospy.has_param('to_delete'):
00086         rospy.delete_param('to_delete')
00087         rospy.loginfo("deleted %s parameter"%rospy.resolve_name('to_delete'))
00088     else:
00089         rospy.loginfo('parameter %s was already deleted'%rospy.resolve_name('to_delete'))
00090 
00091     # search for a parameter
00092     param_name = rospy.search_param('global_example')
00093     rospy.loginfo('found global_example parameter under key: %s'%param_name)
00094     
00095     # publish the value of utterance repeatedly
00096     pub = rospy.Publisher(topic_name, String)
00097     while not rospy.is_shutdown():
00098         pub.publish(utterance)
00099         rospy.loginfo(utterance)
00100         rospy.sleep(1)
00101         
00102 if __name__ == '__main__':
00103     try:
00104         param_talker()
00105     except rospy.ROSInterruptException: pass
00106     


rospy_tutorials
Author(s): Ken Conley
autogenerated on Mon Oct 6 2014 06:54:54