I'm following the Flask tutorial here:
http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-i-hello-world
I get to the point where I try ./run.py and I get:
Traceback (most recent call last):
File "./run.py", line 3, in <module>
from app import app
File "/Users/benjaminclayman/Desktop/microblog/app/__init__.py", line 1, in <module>
from flask import Flask
ImportError: No module named flask
This looks similar to:
ImportError: No module named flask
But their solutions aren't helpful. For reference, I do have a folder named flask which one user mentioned may cause issues.
my answer just for any users that use Visual Studio Flesk Web project :
Just Right Click on "Python Environment" and Click to "Add Environment"
For python 3 use
pip3 install flask
/etc/apache2/sites-available/FlaskApp.conf
WSGIDaemonProcess FlaskApp python-home=/var/www/FlaskApp/FlaskApp/venv/FlaskApp
WSGIProcessGroup FlaskApp
service apache2 restart
I'm following the Flask tutorial too.And I met the same problem.I found this way to fix it.
http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-i-hello-world
in my case using Docker, my .env file was not copied, so the following env vars were not set:
.env.local:
FLASK_APP=src/app.py
so in my Dockerfile
i had to include:
FROM deploy as dev
COPY env ./env
which was referenced in docker-compose.yml
env_file: ./env/.env.local
another thing i had to pay attention to is the path variable to ensure my environment is used
ENV PATH $CONDA_DIR/envs/:my_environment_name_from_yml_file:/bin:$CONDA_DIR/bin:$PATH```
If you are using Pycharm then this is the virtual environment issue.
So, at the time of creating your Python project you will have to select "Existing interpreter" option -> click "system Interpreter" -> select the correct option for example "*\AppData\Local\Programs\Python\Python3.6\python.exe".
You can use 'New Virtual Env' as well, but I have just given the quick fix that should work for Pycharm users.
Go to the flask file in microblog, then activate the virtual environment with source bin/activate
, then go to flask/bin and install flask, and the rest of the packages, pip install flask
. You will see flask listed inside bin directory. Try to run ./run.py
again from microblog (or from wherever you have the file).
In my case the solution was as simple as starting up my virtual environment like so:
$ venv/scripts/activate
It turns out I am still fresh to Python :)
It worked for me after upgrading pip:
curl https://bootstrap.pypa.io/get-pip.py | python
Found that answer here: https://stackoverflow.com/a/49748494/3197202
Then I could just install flask:
pip install flask
The flask script is nice to start a local development server, but you would have to restart it manually after each change to your code. That is not very nice and Flask can do better. If you enable debug support the server will reload itself on code changes, and it will also provide you with a helpful debugger if things go wrong. To enable debug mode you can export the FLASK_DEBUG environment variable before running the server: forexample your file is hello.py
$ export FLASK_APP=hello.py
$ export FLASK_DEBUG=1
$ flask run
This is what worked for me when I got a similar error in Windows; 1. Install virtualenv
pip install virtualenve
Create a virtualenv
virtualenv flask
Navigate to Scripts and activate the virtualenv
activate
Install Flask
python -m pip install flask
Check if flask is installed
python -m pip list
I was using python2 but installed this: sudo apt-get install libapache2-mod-wsgi-py3
Instead of: sudo apt-get install libapache2-mod-wsgi
Correcting the installation solved the no flask problem.
enter your python interactive mode then:
import sys
sys.path
it will print your path. Check wether flask is installed in the sys.path.
For MacOS, python path is under /opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages
But pip'll install python package by default under /Library/Python/2.7/site-packages
That's why it doesn't work for MacOS.
this is what worked for me,
sudo -H pip install flask
Or for pip3(python3) use :
sudo -H pip3 install flask
Sidenote
If you're using virtualenv it's a good idea to
pip freeze >> requirements.txt
to allow for the installed packages to be listed in one place.
The sudo
command and -H
flag. For more on sudo
's -H
flag, look at Paul's answer.
Hope this helps you.
I had a similar problem with flasgger.
The reason for that was that I always use
sudo pip install flask
but for some reason that's not always the way to go. Sometimes, you have to do just
pip install flask
Another gotcha is that sometimes people type pip install Flask
with the cap F
Posting this here in case somebody gets stuck. Let me know if it helped.
Useful Link: What is the difference between pip install and sudo pip install?
Even i too suggest u virtualenv, This might also solve ur problem.
sudo apt install python-flask
If u want to deploy in productionserver then go ahead with above solution else use virtualenv.
After activating the virtual environment and installing Flask, I created an app.py file. I run it like this : python -m flask run
. Hope this will help!
Another thing - if you're using python3, make sure you are starting your server with python3 server.py
, not python server.py
The simplest answer to this problem is specifying the correct path to flask in your environment. Make sure the script you are running knows how to get to the flask installation. Using print(sys.path) as mentioned above certainly helped to figure out the path(s) the script was using.
The only way I could solve was by adding my users python dir to myapp.wsgi file. As an example:
sys.path.append('/home/deployer/anaconda3/lib/python3.5/site-packages')
I guess that if you install the packages in the global enviroment, you should have no problem, but I had my python packages installed as user.
Source: Stackoverflow.com