python flask import error

Question

I am running the following code

from flask import Flask
app = Flask(__name__)
@app.route("/")
def hello():
    return "Hello World!"
if __name__ == "__main__":
    app.run(host='0.0.0.0', port=80, debug=True)

and getting the following error

Traceback (most recent call last):
  File "test.py", line 1, in <module>
    from flask import Flask
  File "/home/pi/programs/flask.py", line 1, in <module>
    from flask import Flask
ImportError: cannot import name Flask

I have tried installing flask through various methods , but still the problem persists

also, is there any alternative to flask???

Solution 1

Just run apt-get install python3-flask

Edited to install the python3 version, since nobody should be using python2 now.

Solution 2

I ran into this error because I named the test file as flask.py and tried to run it! It creates namespace conflict with the real flask module!

Delete the local test file that you named flask.py and the respective flask.pyc. Give some other name! This will happen with other modules like socket etc where you are likely to give the same name for the test file as the standard module :-)

Solution 3

The reason is your python file name is flask.

Solution 4

Just rename flask.py file also delete flask.pyc file

Solution 5

It's because of the name flask.py. It will import itself if the name is flask.py. Change the name and try again.

View more solutions

Comments

[Admin]

what ip should give in app.run(host='0.0.0.0', port=80, debug=True) i am getting the following error ** * Running on 0.0.0.0:80 Traceback (most recent call last): File "test.py", line 14, in <module> app.run(host='0.0.0.0', port=80, debug=True) run_simple(host, port, self, **options) File "/usr/local/lib/python2.7/dist-packages/werkzeug/serving.py"‌​, line 613, in run_simple test_socket.bind((hostname, port)) File "/usr/lib/python2.7/socket.py", line 224, in meth return getattr(self._sock,name)(*args) socket.error: [Errno 98] Address already in use **

[LtWorf]

0.0.0.0 is fine, it will listen to all the interfaces. The port is not okay since you need to be root to use that. For testing usually people use 8080.

[Alex]

YES, that's it. This cardinal mistake again...upvote.

[Dendi Suhubdy]

This is the mistake I made. Thanks!

[Gilad]

run "apt-get install python3-flask" if you are running python v3

[Nishant]

sqlalchemy, users also bump into the same issue. they name it as sqlalchemy.py :)

[Barry Michael Doyle]

Could you provided more information to solving the problem?

[Rainbowbreeze]

2017... And this reply is still useful. Thank you and shame on my and on the filename I've chosen!

[Tayyab Anwar]

Thank you so much! I was making the same mistake.

[Víctor López]

That was the real problem. Thanks for sharing it.

[Ken Aspeslagh]

Yikes! that was my problem too

[LukaszTaraszka]

I hate this kind of problems :/

[gented]

Bloody hell, the amount of times I make this same error is unprecedented.

[vielkind]

Could you be more specific about what the name "flask.py" is problematic and what it should be changed to?

[Admin]

@vealkind its because the file will try to import the itself. Write some print statement in flask.py and then import flask in the same file and it will print the same thing twice, so..

[Farley]

You'd think after programming in a language for years you would not forget this simple little gem. I think this is the third time I landed on this page over the years. Thanks again!

[Mina Gabriel]

:) OMG - I don't like when this happens

[demongolem]

For me, it was because I had named a Python package as flask

[interestedparty333]

As you point out, happens with socket too. lolz