我是 Python 和这些库/模块的新手。我正在编写一个简单的 ping 测试网络扫描仪作为学习项目。
我首先使用 asyncio 开发了一个脚本来 ping 网络上的地址
#ip_test.py
import asyncio
import ipaddress
async def ping(addr):
proc = await asyncio.create_subprocess_exec(
'ping','-W','1','-c','3',addr,
stdout=asyncio.subprocess.PIPE
)
await proc.wait()
return proc.returncode
async def pingMain(net):
#hosts() returns list of Ipv4Address objects
result = await asyncio.gather(*(ping(str(addr)) for addr in net.hosts()))
return result
def getHosts(net_): #net_ is an Ipv4Network object
return asyncio.run(pingMain(net_))
#Returns list of response codes which I then zip with the list of searched ips
当我打开 python 并运行以下命令时,它按预期工作:
import ip_test as iptest
import ipaddress
print(iptest.getHosts(ipaddress.ip_network('192.168.1.0/29')))
#prints: [0, 0, 0, 1, 1, 1] as expected on this network
然而,最终目标是通过表单输入获取用户的输入(结果记录到数据库中,这是出于说明目的的简化示例)。我通过烧瓶路线收集输入:
@app.route("/newscan",methods=['POST'])
def newScan():
form = request.form
networkstring = form.get('network') + "/" + form.get('mask')
result = iptest.getHosts(ipaddress.ip_network(networkstring))
return result
当我以这种方式调用模块时,出现错误:Runtime Error: Cannot add child handler, the child watcher does not have a loop attached.
为什么当我导入模块并从命令行运行该函数时它可以工作,但当我使用 Flask 路由中的相同输入调用它时却不起作用?
编辑:回溯:
Traceback (most recent call last):
File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 2463, in __call__
return self.wsgi_app(environ, start_response)
File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 2449, in wsgi_app
response = self.handle_exception(e)
File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 1866, in handle_exception
reraise(exc_type, exc_value, tb)
File "/usr/local/lib/python3.7/site-packages/flask/_compat.py", line 39, in reraise
raise value
File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 2446, in wsgi_app
response = self.full_dispatch_request()
File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 1951, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 1820, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/usr/local/lib/python3.7/site-packages/flask/_compat.py", line 39, in reraise
raise value
File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 1949, in full_dispatch_request
rv = self.dispatch_request()
File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 1935, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/app/app.py", line 41, in newScan
result = iptest.getHosts(ipaddress.ip_network(networkstring))
File "/app/ip_test.py", line 22, in getHosts
res = asyncio.run(pingMain(net_))
File "/usr/local/lib/python3.7/asyncio/runners.py", line 43, in run
return loop.run_until_complete(main)
File "/usr/local/lib/python3.7/asyncio/base_events.py", line 579, in run_until_complete
return future.result()
File "/app/ip_test.py", line 15, in pingMain
result = await asyncio.gather(*(ping(str(addr)) for addr in net.hosts()))
File "/app/ip_test.py", line 7, in ping
stdout=asyncio.subprocess.PIPE
File "/usr/local/lib/python3.7/asyncio/subprocess.py", line 217, in create_subprocess_exec
stderr=stderr, **kwds)
File "/usr/local/lib/python3.7/asyncio/base_events.py", line 1529, in subprocess_exec
bufsize, **kwargs)
File "/usr/local/lib/python3.7/asyncio/unix_events.py", line 193, in _make_subprocess_transport
self._child_watcher_callback, transp)
File "/usr/local/lib/python3.7/asyncio/unix_events.py", line 930, in add_child_handler
"Cannot add child handler, "
RuntimeError: Cannot add child handler, the child watcher does not have a loop attached