在Jupyter Notebook中调试Flask服务器 [英] debug Flask server inside Jupyter Notebook

问题描述

我想在jupyter笔记本中调试小型烧瓶服务器以进行演示.

I want to debug small flask server inside jupyter notebook for demo.

我在最新的Ubuntu和Python2上创建了virtualenv(在使用Python3的Mac上也发生了此错误)，pip安装flask jupyter.

I created virtualenv on latest Ubuntu and Python2 (on Mac with Python3 this error occurs as well), pip install flask jupyter.

但是，当我使用helloworld脚本创建单元时，它无法在笔记本中运行.

However, when I create a cell with helloworld script it does not run inside notebook.

from flask import Flask
app = Flask(__name__)

@app.route("/")
def hello():
    return "Hello World!"

if __name__ == "__main__":
    app.run(debug=True,port=1234)

文件 "/home/***/test/local/lib/python2.7/site-packages/ipykernel/kernelapp.py"， 第177行，在_bind_socket中 s.bind("tcp://％s:％i"％(self.ip，端口))文件"zmq/backend/cython/socket.pyx"，行495，在 zmq.backend.cython.socket.Socket.bind (zmq/backend/cython/socket.c:5653)文件 "zmq/backend/cython/checkrc.pxd"，第25行，在 zmq.backend.cython.checkrc._check_rc (zmq/后端/cython/socket.c:10014) 引发ZMQError(errno)ZMQError:地址已在使用中

File "/home/***/test/local/lib/python2.7/site-packages/ipykernel/kernelapp.py", line 177, in _bind_socket s.bind("tcp://%s:%i" % (self.ip, port)) File "zmq/backend/cython/socket.pyx", line 495, in zmq.backend.cython.socket.Socket.bind (zmq/backend/cython/socket.c:5653) File "zmq/backend/cython/checkrc.pxd", line 25, in zmq.backend.cython.checkrc._check_rc (zmq/backend/cython/socket.c:10014) raise ZMQError(errno) ZMQError: Address already in use

NB-每次失败后，我都要更改端口号.

NB - I change the port number after each time it fails.

当然，它可以作为独立脚本运行.

Sure, it runs as a standalone script.

无需(debug = True)更新就可以.

update without (debug=True) it's ok.

推荐答案

我安装了Jupyter和Flask，您的原始代码也可以正常工作.

I installed Jupyter and Flask and your original code works.

flask.Flask对象是WSGI应用程序，而不是服务器.当您在Shell中调用python -m flask run时，Flask将Werkzeug的开发服务器用作WSGI服务器.它创建一个新的WSGI服务器，然后将您的应用程序作为参数传递给werkzeug.serving.run_simple.也许您可以尝试手动执行此操作:

The flask.Flask object is a WSGI application, not a server. Flask uses Werkzeug's development server as a WSGI server when you call python -m flask run in your shell. It creates a new WSGI server and then passes your app as paremeter to werkzeug.serving.run_simple. Maybe you can try doing that manually:

from werkzeug.wrappers import Request, Response
from flask import Flask

app = Flask(__name__)

@app.route("/")
def hello():
    return "Hello World!"

if __name__ == '__main__':
    from werkzeug.serving import run_simple
    run_simple('localhost', 9000, app)

Flask.run()在内部调用run_simple()，因此此处应该没有区别.

Flask.run() calls run_simple() internally, so there should be no difference here.

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