launch文件报错

[643755361]

虚拟机安装的ubuntu20.04，ros2版本foxy,在编写launch文件启动节点时遇到如下错误：
[INFO] [launch]: All log files can be found below /home/daisy/.ros/log/2023-12-07-14-31-39-216423-daisy-VirtualBox-9375
[INFO] [launch]: Default logging verbosity is set to INFO
Task exception was never retrieved
future: <Task finished name='Task-2' coro=<LaunchService._process_one_event() done, defined at /opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py:226> exception=InvalidLaunchFileError('py')>
Traceback (most recent call last):
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_description_sources/any_launch_file_utilities.py", line 53, in get_launch_description_from_any_launch_file
return loader(launch_file_path)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_description_sources/python_launch_file_utilities.py", line 68, in get_launch_description_from_python_launch_file
return getattr(launch_file_module, 'generate_launch_description')()
File "/home/daisy/test2/src/install/print/share/print/launch/print.launch.py", line 9, in generate_launch_description
return LaunchDescription(generate_launch_description)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_description.py", line 55, in init
self.__entities = list(initial_entities) if initial_entities is not None else []
TypeError: 'function' object is not iterable

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py", line 228, in _process_one_event
await self.__process_event(next_event)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py", line 248, in __process_event
visit_all_entities_and_collect_futures(entity, self.__context))
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 38, in visit_all_entities_and_collect_futures
sub_entities = entity.visit(context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/action.py", line 108, in visit
return self.execute(context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/actions/include_launch_description.py", line 130, in execute
launch_description = self.__launch_description_source.get_launch_description(context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_description_source.py", line 84, in get_launch_description
self._get_launch_description(self.__expanded_location)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_description_sources/any_launch_description_source.py", line 53, in _get_launch_description
return get_launch_description_from_any_launch_file(location)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_description_sources/any_launch_file_utilities.py", line 56, in get_launch_description_from_any_launch_file
raise InvalidLaunchFileError(extension, likely_errors=exceptions)
launch.invalid_launch_file_error.InvalidLaunchFileError: Caught exception when trying to load file of format [py]: 'function' object is not iterable
daisy@daisy-VirtualBox:~/test2/src$ colcon build --packages-select print
Starting >>> print
Finished <<< print [1.24s]

Summary: 1 package finished [2.34s]
daisy@daisy-VirtualBox:~/test2/src$ source install/setup.bash
daisy@daisy-VirtualBox:~/test2/src$ ros2 launch print.launch.py
Package 'print.launch.py' not found: "package 'print.launch.py' not found, searching: ['/home/daisy/test2/src/install/print', '/home/daisy/test2/src/install/village_interface', '/opt/ros/foxy']"
daisy@daisy-VirtualBox:~/test2/src$ ros2 launch print print.launch.py
[INFO] [launch]: All log files can be found below /home/daisy/.ros/log/2023-12-07-14-34-04-971162-daisy-VirtualBox-9556
[INFO] [launch]: Default logging verbosity is set to INFO
Task exception was never retrieved
future: <Task finished name='Task-2' coro=<LaunchService._process_one_event() done, defined at /opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py:226> exception=InvalidLaunchFileError('py')>
Traceback (most recent call last):
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_description_sources/any_launch_file_utilities.py", line 53, in get_launch_description_from_any_launch_file
return loader(launch_file_path)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_description_sources/python_launch_file_utilities.py", line 68, in get_launch_description_from_python_launch_file
return getattr(launch_file_module, 'generate_launch_description')()
File "/home/daisy/test2/src/install/print/share/print/launch/print.launch.py", line 9, in generate_launch_description
return LaunchDescription(generate_launch_description)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_description.py", line 55, in init
self.__entities = list(initial_entities) if initial_entities is not None else []
TypeError: 'function' object is not iterable

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py", line 228, in _process_one_event
await self.__process_event(next_event)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py", line 248, in __process_event
visit_all_entities_and_collect_futures(entity, self.__context))
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 38, in visit_all_entities_and_collect_futures
sub_entities = entity.visit(context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/action.py", line 108, in visit
return self.execute(context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/actions/include_launch_description.py", line 130, in execute
launch_description = self.__launch_description_source.get_launch_description(context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_description_source.py", line 84, in get_launch_description
self._get_launch_description(self.__expanded_location)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_description_sources/any_launch_description_source.py", line 53, in _get_launch_description
return get_launch_description_from_any_launch_file(location)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_description_sources/any_launch_file_utilities.py", line 56, in get_launch_description_from_any_launch_file
raise InvalidLaunchFileError(extension, likely_errors=exceptions)
launch.invalid_launch_file_error.InvalidLaunchFileError: Caught exception when trying to load file of format [py]: 'function' object is not iterable

节点程序：
import rclpy
from rclpy.node import Node
from std_msgs.msg import String,UInt32 # 导入消息类型，这里是字符串,整形
from village_interface.srv import BorrowMoney

class Print(Node):
def init(self, name):
super().init(name)
# self.get_logger().info("hahhhahha")
# 发布小说 (话题的类型， 话题的name, 这个参数在研究研究)
self.pub_novel = self.create_publisher(String, "sexy_girl", 10)
# 定时发布(周期, 回调hafunction)
self.count = 0
self.masage = String()
self.t = 5
self.timer = self.create_timer(self.t, self.call_back_fun)

    self.account = 80   #账户
    # 收钱(类型，name，回调函数， 10不懂)
    # self.submoney = self.create_subscription(UInt32,"money", self.money_callback, 10)
    # 创建服务端
    # self.borrow_serve = self.create_service(BorrowMoney, "borrow_money",self.borrowmoney_callback)
def call_back_fun(self):
    # msg = String()
    self.masage.data = "lala%d,;alal%d" % (self.count, self.count)
    self.pub_novel.publish(self.masage)
    self.get_logger().info("%s" % self.masage.data)
    self.count += 1
# def money_callback(self, money):
    # self.account += money.data
    # self.get_logger().info("shoudao%d的稿费,现在有%d" % (money.data,self.account))

def borrowmoney_callback(self,requst,response):

# self.get_logger().info("%s, %d"%(requst.name, self.account))
# if request.money <= self.account*0.1:
#    response.success = True
#    response.money = request.money
# else:
#     response.success = False
#     response.money = 0
# return response

def main(args = None):

rclpy.init(args = args)
# my_print = Node("print")
# my_print.get_logger().info("lalallalallalal")
my_print = Print("print")
rclpy.spin(my_print)
rclpy.shutdown()

launch 文件：
from launch import LaunchDescription
from launch_ros.actions import Node

def generate_launch_description():
my_print = Node(
package = 'print',
executable = 'my_print'
)
return LaunchDescription(generate_launch_description)

setup 文件：
from setuptools import setup
import os
from glob import glob

package_name = 'print'

setup(
name=package_name,
version='0.0.0',
packages=[package_name],
data_files=[
('share/ament_index/resource_index/packages',
['resource/' + package_name]),
('share/' + package_name, ['package.xml']),
(os.path.join('share',package_name,'launch'),glob('launch/*.py'))
],
install_requires=['setuptools'],
zip_safe=True,
maintainer='daisy',
maintainer_email='daisy@todo.todo',
description='TODO: Package description',
license='TODO: License declaration',
tests_require=['pytest'],
entry_points={
'console_scripts': [
"my_print = print.my_print:main"
],
},
)