Worked on the srinivasreddy/cpython repository to enhance the accuracy of zip file detection within the Python standard library. Addressed a bug in the zipfile.is_zipfile function by refining its validation logic, which reduced false positives when identifying zip archives. This targeted backend change improved the reliability of archive detection across packaging and I/O workflows, minimizing misclassification risks and potential downstream errors. The solution was implemented using Python and validated through unit testing to ensure regression safety. The work focused on a small, well-scoped fix, demonstrating attention to detail and a methodical approach to improving core backend functionality.