CSS Problems with Flask Web App


I can't get the CSS to output correctly - my webpages are all unstyled.

This is my link in all my templates. What am I doing wrong?

<link type="text/css" rel="stylesheet" href="/stylesheets/style.css"/>

Is there anything special that I have to do with Flask to get it to work?

I've been trying and changing things for about half an hour but can't seem to get it right.

To sum it up: How do you do CSS with Flask - do I have to have any special python code?

12/7/2012 11:55:18 PM

Accepted Answer

You shouldn't need to do anything special with Flask to get CSS to work. Maybe you're putting style.css in flask_project/stylesheets/? Unless properly configured, such directories won't be served by your application. Check out the Static Files section of the Flask Quickstart for some more information on this. But, in summary, this is what you'd want to do:

  1. Move static files you need to project_root/static/. Let's assume that you moved stylesheets/style.css into project_root/static/stylesheets/style.css.

  2. Change

    <link ... href="/stylesheets/style.css" />


    <link ... href="{{ url_for('static', filename='stylesheets/style.css') }}" />

    This tells the template parser (Jinja2) to tell Flask to find the configured static directory in your project directory (by default, static/) and return the path of the file.

    • If you really wanted to, you could just set the path as /static/stylesheets/style.css. But you really shouldn't do that - using url_for allows you to switch your static directory and still have things work, among other advantages.

And, as @RachelSanders said in her answer:

In a production setting, you'd ideally serve your static files via apache or nginx, but this is good enough for dev.

12/8/2012 12:57:50 AM

4 steps to do this (building a lot on some of the other answers here, presuming you've got Flask all set up properly):

1) Create a static folder in your app folder:[root_folder]/app/static/

2) Move all of your static content (images, JavaScript, CSS, etc.) into those folders. Keep the content in their respective folders (not mandatory, just neater and more organized).

3) Modify your __init__.py file in the app folder to have this line:

app.static_folder = 'static'

This will allow your app to identify your static folder and read it accordingly.

4) In your HTML, set up your file links as such:

<link ... href="{{ url_for('static', filename='[css_folder]/[css-file].css') }}" />

For example, if you call your CSS folder 'stylesheets' and file 'styles':

<link ... href="{{ url_for('static', filename='stylesheets/styles.css') }}" />

That should set everything up properly. Good luck!

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