I'm trying to get a Flask "hello world" application working on a Dreamhost shared server, following the instructions on their wiki, but I'm not having any luck.
My Flask application is the "hello world" one from the Flask quickstart guide:
from flask import Flask
app = Flask(__name__)
#app.route('/')
def hello_world():
return 'Hello World!'
if __name__ == '__main__':
app.run()
Which I've got in a file called "hello.py" in a folder called mysite, as per the DH wiki instructions. My passenger_wsgi.py file is:
import sys, os
INTERP = os.path.join(os.environ['HOME'], 'flask_env', 'bin', 'python')
if sys.executable != INTERP:
os.execl(INTERP, INTERP, *sys.argv)
sys.path.append(os.getcwd())
from mysite import hello as application
I've tried running the commands in a Python console, and last import line failed until I added the __init__.py file to the mysite directory.
When I try and access the website I just get a 500 error (and nothing in the logs unfortunately, unless they're in logs I can't get to as this is a shared server...).
As this is the most basic of setups (i.e., copied and pasted from a wiki), I can't help feeling that I'm missing something really simple. Or perhaps this isn't possible on a shared server?
Does answering my own question mean I'm talking to myself?
Anyway - I seem to have fixed it. Rather than find a nice helpful error message, I went through all the steps again one at a time, and it turns out it was an import error in the passenger_wsgi.py file. As the app is in the mysite subdirectory, the line:
from mysite import hello as application
should have been (and in fact, now is):
from mysite.hello import app as application
And it works. Which is nice.
Related
i have a strange experience with Python code, so:
Im trying to learn Flask with some tutorial, and i managed to follow some with nice result, and now im trying to start my own project to make sure i understood the stuff, but i find myself stuck by hours for this problem
I have this directory structure:
/projectName/
/venv/
/website/
/static/
/templates/
/__init__.py
/otherPython.py
/app.py
app.py
from website import create_app
app = create_app()
if __name__ == '__main__':
app.run(debug=True)
init.py
from flask import Flask
def create_app():
# I create the app and give the secret key
app = Flask(__name__)
app.config['SECRET_KEY'] = 'stackoverflow'
return app
The Problem
Cannot find reference 'create_app' in 'imported module website'
Enviroment:
Win10 pro 10.0.19045
python 3.10
PyCharm 2022.1.4 (community edition)
Does somebody have any clue on what im missing, or if im allucinating and dont see a clear code/path error?
In a identical project it works, i already tryied to mark ProjectFolder as Source Root, already tryed to clean caches and restart, and i cannot understand why as a identical import with same folder structura and method name, in one project work(the tutorial one), and now in mine doesnt.
I dont know if that is helpfull but after from website import if i do ctrl+space i do not see the init.py file nor the create_app() method.
i am trying to import create_app from init.py that is located in the website file
but everytime I try to run the code I get
ImportError: cannot import name 'create_app' from 'website' (unknown location)
this is my files
.vscode
env
website
--static
--templates
--__init__.py
--auth.py
--views.py
--models.py
main.py
init.py
from flask import Flask
def create_app():
app = Flask(__name__)
app.config['SECRET_KEY'] = 'hello'
return app
main.py
from website import create_app
app = create_app
if __name__ == '__main__':
app.run(debug=True)
thought this is the only method that isn't working I tried this method to check if the error is from vscode but it is just from this method
I tried
app.py
from flask import Flask
app = Flask(__name__)
#app.route("/")
def home():
return "hello Flask"
and when I write in the terminal `python -m flask run
I would get a website that says "hello Flask"
but when I press the run icon I get nothing
unlike the first one if I run it I would get an import error unknown location
and if I use python -m flask run I would get
Error: could not locate a Flask application. You did not provide the "FLASK_APP" environment variable, and a "wsgi.py" or "app.py" module not found in the current directory.
thought everything is sync to Github
in both of them I am working in a 'script' environment
A fix I came up with was adding name to the function defining create_app inside the init file.
Example:
from flask import Flask
def create_app(name):
app = Flask(name)
When importing, try from website.templates import create_app. So basically after you put it to import from website, add . following the sub-folder that you desired to import from (in this case it is templates).
I ran into the same thing, but it appears that these files "models, views, etc" isn't in website folder, they are inside static folder which is in website folder, that's why it's not working.
I just fixed them manually.
For someone getting this error later (like myself), be sure to check that your main package's
__init__.py
file is in the correct place.
You forgot create environment variable.
if you using mac or linux export FLASK_APP=main.py
if you windows set FLASK_APP=main.py
And last in main.py should be app = create_app()
try this
in your main.py
from website.init import create_app
or
change file init to init.py
then in your main.py
from website._init_ import create_app
Trying to run the flask code in Vscode (mac Os x 10.14.15) but getting an error.
First I tried running:
python3 -m flask run
But, it showed
"Could locate a Flask application. You didnt provide Flask_App variable or wsgi.py or app.py was not found in the current directory.
I then ran the following command:
export Flask_app = app.py
(though I didnt need to export the variable since my file name is already app.py)
flask run
Could not import 'app'
Please note that I have verified that Flask version 1.0.3 is installed
Here is the code I'm trying to execute:
from flask import Flask
app = Flask(__name__)
#app.route("/")
def home():
return "Hello, Flask!"
Python script should have been created in env/bin. Program ran successfully after moving .py file in the bin folder.
I am writing a flask application with PyCharm. But Pycharm couldn't recognize Flask module. Flask installed globally on my computer as seen on screenshot. I tried virtualenv also but nothing change. Still can't find Flask. I can run Flask anywhere except Pycharm succesfully. My operating system is Windows by the way.
Here is my code snippet
from flask import Flask, render_template, url_for
app = Flask(__name__)
#app.route("/")
#app.route("/home")
def home():
return render_template("home.html")
if __name__ == "__main__":
app.run(debug=True)
Change the name of your file from flask.py to something else and it will work. Naming your file flask.py causes Python to look in your file for the Flask class, and it fails.
Naming a file site.py causes this issue.
It looks like a module named "site" is involved in importing the installed libraries, so by creating a module of the same name I prevent flask from being discovered.
Renaming my file from site.py to something else fixed the issue for me.
After successfully completing the pythonanywhere flask tutorial (pa.com), Miguel Grinberg's the "Flask Mega Tutorial" (fmt) beckoned. Sadly, I've not even made it to "Hello, World". Here's what I have done:
In pa.com attempting to follow fmt verbatim is a no go:
python3 -m venv flask
leads to an error of
ensurepip is not available
and we do not have sudo access.
Undeterred, I reasoned that all Miguel is asking us to do is distribute the functionality we see in one file in the pa.com tutorial (flask_app.py) into a few files that will make the building of a full app easier. Since pa.com is already setting up my base web app with flask and python 3.4, not being able to set up the virtual env. did not seem to be a block, at least not at first.
Per the fmt, in the base dir of the pa.com (pwd -> home/{username}/microblog) -- which is where the flask_app.py file that successfully generates the pa.com tutorial page lives -- I set up app and tmp directories, and create app/__init__.py, app/views.py and the run.py files as directed by fmt
Hitting the app page (run.py the only file in the main directory) generates an Unhandled Exception on the page.
Changing the name to flask_app.py (which seems to be what pa.com expects on flask installations) generates the same error.
Modifying the content of the flask_app.py code to:
from flask import Flask
app = Flask(__name__)
#app.route('/')
def hello_world():
return "working from flask_app.py"
Generates a successful output from the app, whereas having the same code in a file named run.py generates the same Unhandled Exception error.
the lines:
from app import app in both run.py and views.py and
from app import views in __init__.py
all make me wonder... where is this "app" module coming from? But aside from being puzzled by that question, no other ideas on how to proceed from here. Any suggestions? Would really like to get set up on pa.com and work through this tutorial/book.
Feel like I am missing something basic, but not sure what.
First rule is: don't use app.run() on PythonAnywhere - that's what run.py is trying to do. That's fine for your own PC, but on PA it will cause an error. It's fine to have the file there, but don't try and import from that file in your wsgi config.
Instead, you just need to import the flask app variable, which Miguel gets you to put in app/__init__.py (that's slightly confusing, a variable called app, and a folder called app, but we can deal with it!)
To do that, you'll want to add the folder that contains the app folder to your sys.path. You also need to "rename" the app variable to application as you import it:
# assuming we have /home/myusername/microblog/app/__init__.py:
path = '/home/myusername/microblog'
if path not in sys.path:
sys.path.append(path)
# now we can import the app variable from the app folder's __init__
# and rename it to application
from app import app as application
More info: a brief guide to flask on pythonanywhere and a guide to debugging imports and sys.path problems in your pythonanywhere wsgi file
from microblog import app as application
This is fixed my solution.
Best Regards