In this paper, we present DF2, a distribution-free decision-driven learning method, to address three major bottlenecks (model mismatch error, sample mean approximation error, and gradient approximation error) of recently emerged decision-driven learning (DFL) as a powerful approach to prediction-optimization problems. While traditional DFL relies on precise model assumptions of task-specific predictors, DF2 directly learns the expectation optimization function during training. It efficiently learns the function in a data-driven manner by employing an attention-based model architecture inspired by distribution-based parameterization of the expectation objective function. We demonstrate the effectiveness of DF2 through evaluations on two synthetic and three real-world problems.