ValueError: signal only works in main thread

問題:

Traceback (most recent call last):
  File "/home/python/.virtualenvs/toutiao/lib/python3.6/site-packages/flask/_compat.py", line 35, in reraise
    raise value
  File "/home/python/toutiao-backend/toutiao/__init__.py", line 6, in <module>
    import socketio
  File "/home/python/.virtualenvs/toutiao/lib/python3.6/site-packages/socketio/__init__.py", line 3, in <module>
    from .client import Client
  File "/home/python/.virtualenvs/toutiao/lib/python3.6/site-packages/socketio/client.py", line 5, in <module>
    import engineio
  File "/home/python/.virtualenvs/toutiao/lib/python3.6/site-packages/engineio/__init__.py", line 3, in <module>
    from .client import Client
  File "/home/python/.virtualenvs/toutiao/lib/python3.6/site-packages/engineio/client.py", line 44, in <module>
    original_signal_handler = signal.signal(signal.SIGINT, signal_handler)
  File "/usr/lib64/python3.6/signal.py", line 47, in signal
    handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))
ValueError: signal only works in main thread

解決方法:

推測與項目中socketio有關


1.socketio 插件在使用flask run啟動，出現 ValueError: signal only works in main thread 異常的問題。

如果非要flask run啟動，flask run --no-reload 切記一定要帶 --no-reload 參數，本人測試已經成功。

2.如果是使用app.run啟動,run()指定參數use_reloader=False, 這個方法我還沒進行嘗試

app.run(debug=True, use_reloader=False)