I would like to get a single message from a topic. Is there a built-in, simple, elegant way to do this? Currently, I am creating a subscriber, and using a threading.Event object to signal when it receives a message, and automatically unregister itself. It works, but it seems unwieldy for a task that I presume to be fairly common.
class SomeClass:
def __init__(self):
self.data = None
self.get_data_subscriber = None
self.get_data_event = threading.Event()
def get_data_callback(self, data):
self.data = data
self.get_data_subscriber.unregister()
self.get_data_subscriber = None
self.get_data_event.set()
def run(self):
rospy.init_node('myNodeName', anonymous=True)
self.get_data_subscriber = rospy.Subscriber('/sometopic', SomeType, self.get_data_callback)
while True:
self.get_data_event.wait(0.1) # sleep 100ms or wakeup sooner if event was set
# wait() didn't have a return value until python 2.7, so for compatibility, don't rely on the return val.
# is_set() method was added in python 2.6, so for compatibility, use isSet() instead.
if self.get_current_pose_event.isSet():
self.get_current_pose_event.clear()
break
if rospy.is_shutdown():
return
rospy.loginfo("data is: {}".format(data))
return
if __name__ == "__main__":
foo = SomeClass()
foo.run()
Originally posted by rahvee on ROS Answers with karma: 30 on 2018-05-29
Post score: 0
