In modern software development, Python third-party libraries play a critical role, especially in fields like deep learning and scientific computing. However, API parameters in these libraries often change during evolution, leading to compatibility issues for client applications reliant on specific versions. Python’s flexible parameter-passing mechanism further complicates this, as different passing methods can result in different API compatibility. Currently, no tool can automatically detect and repair Python API parameter compatibility issues. To fill this gap, we introduce PCART, the first solution to fully automate the process of API extraction, code instrumentation, API mapping establishment, compatibility assessment, repair, and validation. PCART handles various types of Python API parameter compatibility issues, including parameter addition, removal, renaming, reordering, and the conversion of positional to keyword parameters. To evaluate PCART, we construct PCBENCH, a large-scale benchmark comprising 47,478 test cases mutated from 844 parameter-changed APIs across 33 popular Python libraries. Evaluation results demonstrate that PCART is both effective and efficient, significantly outperforming existing tools (MLCatchUp and Relancer) and the large language model ChatGPT (GPT-4o), achieving an F1-score of 96.51% in detecting API parameter compatibility issues and a repair precision of 91.97%. Further evaluation on 30 real-world Python projects from GitHub confirms PCART’s practicality. We believe PCART can significantly reduce the time programmers spend maintaining Python API updates and advance the automation of Python API compatibility issue repair.

Deep learning (DL) is becoming increasingly important and widely used in our society. DL projects are mainly built upon DL frameworks, which frequently evolve due to the introduction of new features or bug fixing. Consequently, compatibility issues are commonly seen in DL projects. The compatible framework versions may differ across DL projects, i.e., for a specific framework version, one project runs normally while the other crashes, even if the client code uses the same framework API. Existing studies mainly focus on analyzing the API evolution of Python libraries and the related compatibility issues. However, the difference in framework version compatibility (DFVC) among DL projects has rarely been systematically studied. In this paper, we conduct an empirical study on 90 PyTorch and 50 TensorFlow projects collected from GitHub. By upgrading and downgrading the framework versions, we obtain compatible versions for each project and further investigate the root causes of the different compatible framework versions across projects. We summarize seven root causes: Python version, absence of using the same breaking API, import path, parameter, third-party library, resource, and API usage constraint. We further present six implications based on our empirical findings. Our study can facilitate DL practitioners to gain a better understanding of the DFVC among DL projects.

Deep learning (DL) systems are complex component-based systems, which consist of core program (code implementation and data), Python (language and interpreter), third-party libraries, low-level libraries, development tools, OS, and hardware environments. Incompatible interaction between components would cause serious compatibility issues, substantially affecting the development and deployment processes. What types of compatibility issues are frequently exposed in DL systems? What are the root causes of such issues and how do developers fix them? How far are we from automatically detecting and fixing DL compatibility issues? Although there are many existing studies on DL bugs, the characteristics of DL compatibility issues have rarely been systematically studied and the above questions remain largely unexplored. To fill this gap, we conduct the first comprehensive empirical study to characterize compatibility issues in DL systems. Through analyzing 352 DL compatibility issues classified from 3,072 posts in Stack Overflow, we present their types, manifestation stages, and symptoms. We further summarize the root causes and common fixing strategies, and conduct a tool survey on the current research status of automated detection and repair of DL compatibility issues. Our study allows researchers and practitioners to gain a better understanding of DL compatibility issues and can facilitate future tool development.