py中std_msgs.msg.Int32需要导入什么包
时间: 2024-03-16 20:42:43 浏览: 131
在Python中使用`std_msgs.msg.Int32`需要导入`std_msgs`包和`msg`模块。你可以使用以下代码导入它:
```
import rospy
from std_msgs.msg import Int32
```
在这里,`rospy`是ROS Python客户端库,`Int32`是整型消息类型,需要从`std_msgs.msg`模块导入。
相关问题
Traceback (most recent call last): File "sub.py", line 34, in <module> pub_2= rospy.Publisher("/cmd_bucket",std_msgs.msg.Int32,queue_size=10) NameError: name 'std_msgs' is not defined
这个错误提示表明你在代码中尝试使用`std_msgs`包,但是Python解释器找不到这个包的定义。
你需要在代码中导入`std_msgs`包,例如:
```
import rospy
from std_msgs.msg import Int32
pub_2 = rospy.Publisher("/cmd_bucket", Int32, queue_size=10)
```
在这里,我们使用`from std_msgs.msg import Int32`导入了`Int32`消息类型,并将其作为发布器的消息类型,这样你就可以成功创建发布器并发布整型消息了。
Traceback (most recent call last): File "/opt/ros/noetic/lib/python3/dist-packages/std_msgs/msg/_String.py", line 54, in serialize length = len(_x) TypeError: object of type 'int' has no len() During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/opt/ros/noetic/lib/python3/dist-packages/rospy/topics.py", line 882, in publish self.impl.publish(data) File "/opt/ros/noetic/lib/python3/dist-packages/rospy/topics.py", line 1066, in publish serialize_message(b, self.seq, message) File "/opt/ros/noetic/lib/python3/dist-packages/rospy/msg.py", line 152, in serialize_message msg.serialize(b) File "/opt/ros/noetic/lib/python3/dist-packages/std_msgs/msg/_String.py", line 60, in serialize except TypeError as te: self._check_types(ValueError("%s: '%s' when writing '%s'" % (type(te), str(te), str(locals().get('_x', self))))) File "/opt/ros/noetic/lib/python3/dist-packages/genpy/message.py", line 393, in _check_types check_type(n, t, getattr(self, n)) File "/opt/ros/noetic/lib/python3/dist-packages/genpy/message.py", line 285, in check_type raise SerializationError('field %s must be of type bytes or an ascii string' % field_name) genpy.message.SerializationError: field data must be of type bytes or an ascii string During handling of the above exception, another exception occurred: Traceback (most recent call last): File "sub.py", line 45, in <module> pub_2.publish(bucket) File "/opt/ros/noetic/lib/python3/dist-packages/rospy/topics.py", line 886, in publish raise ROSSerializationException(str(e)) rospy.exceptions.ROSSerializationException: field data must be of type bytes or an ascii string
这个错误提示是在ROS中发布消息时的序列化错误。它表明消息中的某个字段必须是字节或ASCII字符串类型,但是实际上它是一个整数类型,无法被序列化。
你需要检查发布代码中的消息格式,确保消息中的所有字段都具有正确的数据类型。如果你使用的是自定义消息,请确保消息定义中的所有字段都已正确定义。你还可以使用ROS中的rostopic echo命令来检查消息是否正确发布。
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