Flask, Keep getting 404 serving static files using send_static_file

You forgot to add 'static' in the last os.path.join in the return clause.

Finally got it working. use flask.send_from_directory

from flask import send_from_directory

@app.route('/js/<path:filename>')
def serve_static(filename):
    root_dir = os.path.dirname(os.getcwd())
    return send_from_directory(os.path.join(root_dir, 'static', 'js'), filename)

It is now clear to me that flask really hate people putting app.py or in my case main.py into a subdirectory. Use send_static_file only if your static folder is what flask thinks to be, i.e. a folder with name static in the same directory with app.py.

All you need to do is, pass the static_folder parameter to the initiator:

static_url_path – can be used to specify a different path for the static files on the web. Defaults to the name of the static_folder folder.

static_folder – the folder with static files that should be served at static_url_path. Defaults to the 'static' folder in the root path of the application.

app = Flask(__name__, static_folder=os.path.abspath('/foo/bar/zoo/'))

Now, flask will look for a directory named static in /foo/bar/zoo from where to serve static files. You only use send_from_directory if you are serving media files which may not be in the same location as static files.