app/__init__.py

from flask import Flask

def create_app():
    v_app = Flask(__name__)
    v_app.config['UPLOAD_FOLDER'] = 'app/uploads/'
    v_app.config['ALLOWED_EXTENSIONS'] = {'zip'}

    with v_app.app_context():
        from .routes import v_bp
        v_app.register_blueprint(v_bp)

    return v_app