register_blueprint doesn't add route to Flask app

Question

I created a blueprint with a route and registered the blueprint with my Flask app. However, I get a 404 when requesting the route. What is wrong with my code?

Answer 1

You registered the blueprint before the code that registered the route executed. Move register_blueprint after the blueprint has been fully defined.

bp = Blueprint('test', __name__, url_prefix='/test')

@bp.route('/')
def home():
    return 'Hello, World!'

app.register_blueprint(bp)