[danjac]

Depends what you want to do, and why you're doing it. Very often when I make something in Flask, I end up with so many dependencies it might as well be Django (but without the cohesion). On the other hand, Django might be overkill in some situations (e.g. a small API without a relational database backend).

[otherme123]

I was forced to fall on this trap once: a guy has a small Flask app up and running, and he asked for help to implement: an ORM with migrations, an Admin and form validation (among other things that had nothing to do with Django such file parsing).

I suggested to migrate the app from Flask to Django while it was small and simple, but he refused for Django is "too big and complicated". OK, then. We ended up creating a monstrosity of Flask half-assed packages to include functionality that is already included in Django (think cache, csrf, admin...), plus WTForms, plus SQLAlchemy, plus Alembic, hard to test, hard to keep updated, hard to deploy, and so complex that it turned non-migrable to Django. Development felt like walking through mud.

[andybak]

I like to paraphrase Greenspun's Tenth Law in this context:

"Any sufficiently complicated Flask app contains an ad-hoc, informally-specified, bug-ridden, slow implementation of half of Django"

[wirthjason]

I love the paraphrased quote. It’s a bit ironic in that Python programmers love the batteries included standard library but quickly jettison that idea when it comes to Django vs Flask.

Flask’s marketing of a simple route decorator makes it seem light weight but once you add everything else it becomes Django.

[dagw]

but he refused for Django is "too big and complicated". OK, then. We ended up creating a monstrosity of Flask half-assed packages to include functionality that is already included in Django (think cache, csrf, admin...), plus WTForms, plus SQLAlchemy, plus Alembic, hard to test, hard to keep updated, hard to deploy...

Heh. I've done that. Impressive how quickly you can go from "I literally need three or four REST end points to let users query this SQLite database" to, well that.

[wilsonfiifi]

I think one common misconception is that Django can't be used in place of Flask when you want a minimalist set up. And to be fair, I used to think the same until I read Lightweight Django [0]. Their smallest django project code is just a couple of lines:

    import sys
    from django.conf import settings 
    settings.configure(
        DEBUG=True,
        SECRET_KEY='thisisthesecretkey',
        ROOT_URLCONF=__name__,
        MIDDLEWARE_CLASSES=(
            'django.middleware.common.CommonMiddleware',
            'django.middleware.csrf.CsrfViewMiddleware',
            'django.middleware.clickjacking.XFrameOptionsMiddleware',
            ),
        )
        
    from django.conf.urls import url
    from django.http import HttpResponse


    def index(request):
        return HttpResponse('Hello World')
        

    urlpatterns = (
        url(r'^$', index),
    )

    if __name__ == "__main__":
        from django.core.management import execute_from_command_line

        execute_from_command_line(sys.argv)

Granted, it's not as terse as Flask's hello world example but it's still quite short.

[0] https://www.oreilly.com/library/view/lightweight-django/9781...

[danjac]

I think the comparison is not so much lines of code but conceptual overhead. With Flask you create an app instance and call @app.route() with some Python functions and run the app. Granted it's probably not going to do much, and by the time you build out a real-world application with a SQL database, authentication and so forth you're going to get diminishing returns, but for a beginner who just wants to know "how do I make a web page using Python?" it's great.

[Avamander]

How big is the smallest Django project after you add proper authentication (signup, login, pw reset, oauth2, 2FA)? Last I checked it was rather terrible.

[varispeed]

Django has a substantial learning curve and you may need to spend more time to get started. But ultimately to do the same thing in Flask you have to spend comparable time to learn, except that Flask lets you start much quicker into your learning. As your Flask project grows you find out it is not actually that easy nor convenient. This is of course my experience only. I decided to just stick to Django (and DRF) and I feel no need to use anything else. For performant services I use Go.