Flask confusion with app
Question:
I am starting a flask project, and in my code I have
from flask import Flask, render_template, abort
app = Flask(__name__)
Now what exactly is app?
I am following this guide and I am particularly confused about the structure because he has chosen to have directory named app/ and is his app/__init__.py he has
from flask import Flask
app = Flask(__name__)
from app import views
and in his app/views.py he has
from app import app
What the hell is it with all these app‘s?!
Answers:
The author made his code needlessly confusing by choosing a package name that is the same as Flask’s usual application object instance name. This is the one you’ll be most interested in:
app = Flask(__name__)
Here is the documentation on the Flask application object:
http://flask.pocoo.org/docs/api/#application-object
To avoid confusion, I recommend using the official Flask documentation instead of that guide.
That’s a bit confusing indeed, due to the poor names choice.
app = Flask(__name__): here app is a WSGI application, it implements the corresponding interface and also supports whatever Flask has to offer us on top of that.from app import app : imports exactly that app object from the package app.from app import view: For what heck he’s importing views there, is a bit of a mystery, I suppose he wants to make sure that the view bindings are executed. (I’d rather do that in run.py). In any case, that’s a kind of importing loop between two modules which is at least confusing as well.
I think the main confusion is in the line:
from app import app
You have a python package (a folder with __init__.py file) named “app”. From this folder, you are now importing the variable “app” that you defined below in __init__.py file:
app = Flask(__name__)
Rename the folder from app to say “myproject”. Then you will call
from myproject import app
Also, you will import views as
from myproject import views
I am starting a flask project, and in my code I have
from flask import Flask, render_template, abort
app = Flask(__name__)
Now what exactly is app?
I am following this guide and I am particularly confused about the structure because he has chosen to have directory named app/ and is his app/__init__.py he has
from flask import Flask
app = Flask(__name__)
from app import views
and in his app/views.py he has
from app import app
What the hell is it with all these app‘s?!
The author made his code needlessly confusing by choosing a package name that is the same as Flask’s usual application object instance name. This is the one you’ll be most interested in:
app = Flask(__name__)
Here is the documentation on the Flask application object:
http://flask.pocoo.org/docs/api/#application-object
To avoid confusion, I recommend using the official Flask documentation instead of that guide.
That’s a bit confusing indeed, due to the poor names choice.
app = Flask(__name__): hereappis a WSGI application, it implements the corresponding interface and also supports whatever Flask has to offer us on top of that.from app import app: imports exactly thatappobject from the packageapp.from app import view: For what heck he’s importingviewsthere, is a bit of a mystery, I suppose he wants to make sure that the view bindings are executed. (I’d rather do that inrun.py). In any case, that’s a kind of importing loop between two modules which is at least confusing as well.
I think the main confusion is in the line:
from app import app
You have a python package (a folder with __init__.py file) named “app”. From this folder, you are now importing the variable “app” that you defined below in __init__.py file:
app = Flask(__name__)
Rename the folder from app to say “myproject”. Then you will call
from myproject import app
Also, you will import views as
from myproject import views