我有一个简单的类Test，该类在下面启动了Google Compute Engine VM，然后通过调用函数（ explicit ）或通过{{ 1}}（隐式）。
__del__与class Test:
def __init__(self):
os.environ['GOOGLE_APPLICATION_CREDENTIALS'] = 'secret.json'
self._compute = googleapiclient.discovery.build('compute',
'v1',
cache_discovery=False)
print('starting vm')
req = self._compute.instances().start(project='test-project',
zone='us-east1-b',
instance='test-vm',
requestId=uuid.uuid1())
self.execute(req)
self._running = True
def stop(self):
print('stopping vm')
req = self._compute.instances().stop(project='test-project',
zone='us-east1-b',
instance='test-vm',
requestId=uuid.uuid1())
self.execute(req)
self._running = False
def execute(self, req):
print(f'method({req.methodId})')
resp = req.execute()
while resp['status'] != 'DONE':
time.sleep(1)
resp = req.execute()
return resp
def __del__(self):
if self._running:
print('stopping in destructor')
self.stop()
类的交互如下：
Test使用显式方法（即：在对象开始被破坏之前调用if __name__ == '__main__':
print('start test')
t = Test()
print('vm running, wait 5 seconds')
time.sleep(5)
if len(sys.argv) == 2 and sys.argv[1] == 'stop':
t.stop()
print('test done')
之前），VM停止运行：
t.stop()但是，当使用隐式方法（即：依靠$ ./test.py stop
start test
starting vm
method(compute.instances.start)
vm running, wait 5 seconds
stopping vm
method(compute.instances.stop)
test done
超出范围并调用t）时，我从Test::__del__堆栈：
googleapiclient问题：
$ ./test.py
start test
starting vm
method(compute.instances.start)
vm running, wait 5 seconds
test done
stopping in destructor
stopping vm
method(compute.instances.stop)
Exception ignored in: <bound method Test.__del__ of <__main__.Test object at 0x7fe091720320>>
Traceback (most recent call last):
File "./test.py", line 46, in __del__
File "./test.py", line 32, in stop
File "./test.py", line 37, in execute
File "/src/test/.venv/lib/python3.6/site-packages/googleapiclient/_helpers.py", line 130, in positional_wrapper
File "/src/test/.venv/lib/python3.6/site-packages/googleapiclient/http.py", line 846, in execute
File "/src/test/.venv/lib/python3.6/site-packages/googleapiclient/http.py", line 183, in _retry_request
File "/src/test/.venv/lib/python3.6/site-packages/googleapiclient/http.py", line 164, in _retry_request
File "/src/test/.venv/lib/python3.6/site-packages/google_auth_httplib2.py", line 198, in request
File "/src/test/.venv/lib/python3.6/site-packages/httplib2/__init__.py", line 1926, in request
File "/src/test/.venv/lib/python3.6/site-packages/httplib2/__init__.py", line 1595, in _request
File "/src/test/.venv/lib/python3.6/site-packages/httplib2/__init__.py", line 1502, in _conn_request
File "/usr/lib/python3.6/http/client.py", line 1239, in request
File "/usr/lib/python3.6/http/client.py", line 1285, in _send_request
File "/usr/lib/python3.6/http/client.py", line 1234, in endheaders
File "/usr/lib/python3.6/http/client.py", line 1026, in _send_output
File "/usr/lib/python3.6/http/client.py", line 986, in send
File "/usr/lib/python3.6/ssl.py", line 975, in sendall
File "/usr/lib/python3.6/ssl.py", line 944, in send
File "/usr/lib/python3.6/ssl.py", line 642, in write
ssl.SSLError: Underlying socket connection gone (_ssl.c:2067)
阻止我的VM非法吗？Test::__del__时，访问Test::__del__不再安全吗？