February 2026 (2026-02) monthly summary for developer work across three repositories. Key features delivered and bugs fixed, impact, and skills demonstrated. Key features delivered: - modal-labs/modal-examples: File Handle Resource Leak Prevention (bug fix) — commit 231909ec802906128ea0773d5f421e3bd4588809. Fixed resource leaks by ensuring file handles are properly closed in two files, improving resource management and reducing crash risk. - pybamm-team/PyBaMM: File Handle Leak Fix in COMSOL Comparison Scripts (bug fix) — commit 59e93741542836159ee694a17f018f865c8150c2. Implemented context managers for JSON file handling to ensure proper closing of files. - run-llama/llama_index: Bug fix for mutable default argument in load_all_file_paths and version bump to 0.4.2 — commit 3bafd0d0a95930ef4b5f1ffa71b3b583fe58f7cd. Major bugs fixed: - Resolved resource leaks and improper file handling across three projects by introducing explicit closures and context managers. - Eliminated potential shared-state bugs by replacing a mutable default argument in load_all_file_paths and updated package version to reflect the fix. Overall impact and accomplishments: - Increased stability and reliability by preventing resource leaks and unintended state sharing. - Improved adherence to Python best practices (context managers, proper closing of files, avoiding mutable defaults). - Clear release hygiene with a version bump (0.4.2) signaling the fix and progress. Technologies/skills demonstrated: - Python resource management (with statements, context managers) - Bug fixing and code hygiene across multiple repos - Versioning and release management - Collaborative development (co-authored commits)