def generate_context(config):
    """Creates the Flask app context and initializes any extensions such as Celery, Redis, SQLAlchemy, etc.

    Positional arguments:
    config -- partial Flask config dict from generate_config().

    Returns:
    The Flask app instance.
    """
    flask_app = Flask(__name__)
    flask_app.config.update(config)
    flask_app.config["TESTING"] = True
    flask_app.config["CELERY_ACCEPT_CONTENT"] = ["pickle"]

    if "SQLALCHEMY_DATABASE_URI" in flask_app.config:
        db = SQLAlchemy(flask_app)
        db.engine.execute("DROP TABLE IF EXISTS celery_tasksetmeta;")
    elif "REDIS_URL" in flask_app.config:
        redis = Redis(flask_app)
        redis.flushdb()

    Celery(flask_app)
    return flask_app