问题
I copy pasted the flask's 'hello world' app from their website and am trying to run it. I get an error message in Chrome saying
Internal Server Error
The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.
Here is the 'hello world' app straight from flasks website
from flask import Flask
app = Flask(__name__)
@app.route('/')
def hello_world():
return 'Hello World!'
if __name__ == '__main__':
app.debug = True
app.run()
What I have tried:
-temporarily disabling Avast!
-disabling windows firewall
-ensuring that the flask module is installed
This was working a couple days ago actually...
回答1:
I don't know why but when I change
app.run()
to
app.run(port=4996)
it starts working. No idea why the default port is throwing an error. Oh well.
回答2:
Some other process is running on port 5000. It may be you still have an old Flask process running, with broken code. Or a different web server altogether is running on that port. Shut down that process, or run on a different port.
You can switch to using a different port with the port argument to app.run():
app.run(port=8080)
If you can't figure out what process is still bound to port 5000, use the Windows Resource Monitor or run netstat -a -b from a command line. See How can you find out which process is listening on a port on Windows?
回答3:
I think you are trying to copy the route generated through your flask program in cmd by pressing ctrl+c which quits your running flask program . i also have the same problem .just try to type the route generated by your flask program on your browser . it will definitely resolve your problem.
回答4:
For Windows machines you can use the command in cmd:
set FLASK_APP=python_file.py
flask run
回答5:
from flask import Flask
app = Flask(__name__)
@app.route('/')
def index():
return 'Hello World'
if __name__ == '__name__':
app.run()
app.run(port=5000)
回答6:
Where your python file store is, use cmd and then go on your file store directory, then
set FLASK_APP=filename.py
After this your flask run cmd will work.
来源：https://stackoverflow.com/questions/35818713/flask-hello-world-not-working