Flask and React routing

We used catch-all URLs for this.

from flask import Flask
app = Flask(__name__)

@app.route("https://stackoverflow.com/", defaults={'path': ''})
@app.route('/<path:path>')
def catch_all(path):
    return 'You want path: %s' % path

if __name__ == '__main__':
    app.run()

You can also go an extra mile and reuse the Flask routing system to match path to the same routes as client so you can embed the data client will need as JSON inside the HTML response.