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