I am using the standard flask app factoty setup as stated here:
http://flask.pocoo.org/docs/1.0/tutorial/factory/
flaskr/init.py
import os
from flask import Flask
def create_app(test_config=None):
# create and configure the app
app = Flask(__name__, instance_relative_config=True)
app.config.from_mapping(
SECRET_KEY='dev',
DATABASE=os.path.join(app.instance_path, 'flaskr.sqlite'),
)
print('Hello World')
...
return app
I run this app with:
export FLASK_APP=flaskr
export FLASK_ENV=development
flask run
All very standard. But why is the code print("hello world") never executed?
edit
After reboot of my dev sytem the issue is gone. I am sorry I posted this.
Looks like you named the file init.py instead of __init__.py.
I guess you are using an older version of flask (<1.0).
The newest versions (>1.0) allow to detect automatically the function create_app or make_app (source code) to launch the application from CLI flask command.
You can update the flask package, for example with pip :
pip install --upgrade Flask
or add the following lines at the end of the __init__ file to create the application in an explicit way:
if __name__ == "__main__":
app = create_app()
app.run()
Related
I'm using Python 3.7.8
ModuleNotFound: No module named 'SpeechRecognition' appears when I try to run my project.
ModuleNotFound: No module named 'SpeechRecognition'
But it works well when I try it with python -m speech_recognition:
enter image description here
How to start flask app. I recommend to start like this. main.py is flask start script file.
# set flask start script file
export FLASK_APP=main.py
# run flask
python3 -m flask run
# main.py
from flask import Flask
app = Flask(__name__)
#app.route('/')
def hello_world():
return 'Hello, World!'
code
from flask import Flask, render_template, session, request
from flask_session import Session
app = Flask(__name__)
app.config["SESSION_PERMANENT"] = False
app.config["SESSION_TYPE"]= "filesystem"
Session(app)
#app.route("/", methods=["GET", "POST"])
def index():
if session.get("comments") is None:
session["comments"] = []
if request.method == "POST":
comment = request.form.get("comment")
session["comments"].append(comment)
CMD
(env) E:\COURSES\CS50W\lec2\exersice>set FLASK_APP=application.py
(env) E:\COURSES\CS50W\lec2\exersice>python -m flask run
E:\COURSES\CS50W\lec2\exersice\env\Scripts\python.exe: No module named flask
Check this out.
If you are not sure whether you have installed flask or not, try running only flask in the cmd or any terminal.If you get any commands about flask then you can be sure that it is installed or you can install by using
pip install flask
If you are concerned about the versions of the libraries you use for your application, then follow the above mentioned link!
So I'm following a beginners tutorial on Flask and for whatever reason am getting an error on what is essentially the very first step.
I first created an "app" directory where I created a python file for "init.py" which contains the following code:
from flask import Flask
app = Flask(__name__)
from app import routes
I then created a "routes.py" python file in the same directory:
from app import app
#app.route('/')
#app.route('/index')
def index():
return "Hello, World!"
Finally (and this is where the problem stems from), I created a python file named "microblog.py" which is located in the same folder as the "app" directory:
from app import app
I then go to my virtual environment and run (using cmd windows):
set FLASK_APP=microblog.py
So far so good, however when I try to run the following code in cmd:
flask run
I get the following error:
ImportError: cannot import name 'app' from 'app' (C:\Users\Grae_\microblog\app\__init__.py)
If any further clarification is needed, here are my file locations:
C:\Users\Grae_\microblog
C:\Users\Grae_\microblog\app
C:\Users\Grae_\microblog\__init__.py
C:\Users\Grae_\microblog\routes.py
C:\Users\Grae_\microblog\venv
C:\Users\Grae_\microblog\microblog.py
Apologies if this is really obvious, I'm just obviously very new to Flask and have been stuck on this for a while.
Thanks
The issue here is on python package "app". The directory should have a file named __init__.py instead of init.py.
For example, you rename the file init.py to __init__.py and replace content with below code it should work
from flask import Flask
app = Flask(__name__)
def start():
from app import routes
start()
You can do something like this:-
test.py
from flask import Flask
app = Flask(__name__)
#app.route("/")
def index():
return "Index!"
#app.route("/hello")
def hello():
return "Hello World!"
#app.route("/members")
def members():
return "Members"
#app.route("/members/<string:name>/")
def getMember(name):
return name</string:name>
if __name__ == "__main__":
app.run()
In command prompt, run the command-
python test.py
Try the URLs in your browser:
http://127.0.0.1:5000/
http://127.0.0.1:5000/hello
http://127.0.0.1:5000/members
http://127.0.0.1:5000/members/Karan/
I have a few custom cli commands for a flask app I'm writing. I'm following the instructions here:
Command Line Interface
The problem is I do not want to put them all in my app.py file, it will get overbloated. What I would like to do is have my project structure:
project
|_ app.py
|_ cli.py
I thought about using a blueprint, but I get "Blueprint has no attribute 'cli'"
This is what I tried:
cli = Blueprint('cli', __name__) # I knew this would not work but I had to try
#cli.cli.command()
#click.argument('name')
def create_user(name):
print("hello")
Thanks
I would do something like this:
cli.py:
from flask import Flask
import click
def register_cli(app: Flask):
#app.cli.command()
#click.argument('name')
def create_user(name):
print("hello", name)
app.py:
from flask import Flask
from cli import register_cli
app = Flask(__name__)
register_cli(app)
It's common to create and configure (or just configure) app in factory functions.
Trying to add flask-Ask to an existing flask website that uses the runserver pattern where app setup done in init but app.run is called in runserver
/myapp
/myapp
__init__.py
views.py
alexa_views.py
runserver.py
This pattern works fine for Flask ( its recommended for larger apps) but Flask-Ask is failing silently when app.run(debug=True) is called from runserver.py.
If I call app.run(debug=True) in _init__.py and run that then Flask-Ask works fine and Alexa responds.
Any ideas?
code:
alexa_views.py
from flask import blueprints
from flask_ask import Ask, statement
askblueprint = blueprints.Blueprint('alexa', __name__, url_prefix='/alexa')
ask = Ask(blueprint=askblueprint)
#ask.launch
def launch():
return statement (' it works')
init.py
from flask import Flask, blueprints
from myapp.alexa_views import askblueprint
app = Flask(__name__)
app.register_blueprint(askblueprint)
# lots of other unrelated configuration here - db etc
# running app here causes Flask-Ask to work!
# if __name__ == '__main__':
# app.run(debug=True)
# late import of views to break circular import
import myapp.views
runserver.py
# running this starts website normally but Flask-Ask does nothing
from myapp import app
if __name__ == '__main__':
app.run(debug=True)
I am going to close this.
The problem does exist in my real app but this simple example now works fine so I will have to dig deeper to find something I can demonstrate.
Bill