用python编写一个ros2订阅节点代码例程

以下是一个使用Python编写的ROS2订阅节点代码示例：import rclpy
from rclpy.node import Node
class MinimalSubscriber(Node):
def __init__(self):
super().__init__('minimal_subscriber')
self.subscription = self.create_subscription(
std_msgs.msg.String,
'topic',
self.listener_callback,
10)
self.subscription # prevent unused variable warning

def listener_callback(self, msg):
self.get_logger().info('I heard: "%s"' % msg.data)

def main(args=None):
rclpy.init(args=args)
minimal_subscriber = MinimalSubscriber()

rclpy.spin(minimal_subscriber)

# Destroy the node explicitly
# (optional - otherwise it will be done automatically
# when the garbage collector destroys the node object)
minimal_subscriber.destroy_node()
rclpy.shutdown()

if name == 'main':
main()