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## Summary - Moves `nltk`, `spacy`, `sentence-transformers`, and `konlpy` imports back inside class constructors/functions so they are only loaded when the respective splitter is actually instantiated - Adds a subprocess-based regression test to verify no heavy packages are imported at `langchain_text_splitters` load time ## Why PR #32325 moved these optional dependency imports to module-level `try/except` blocks (to satisfy ruff's `PLC0415` rule). Since `__init__.py` imports all four splitter modules, this caused `import langchain_text_splitters` to eagerly load all optional heavy packages, resulting in: - A PyTorch NVML warning (`UserWarning: Can't initialize NVML`) on non-GPU machines - A ~650MB memory spike on import (74MB → 736MB), vs ~50MB in 0.3.x The fix restores the lazy import pattern with `# noqa: PLC0415` to suppress the linter rule, which is the correct trade-off when a dependency has high instantiation cost. ## Review notes - The `PLC0415` suppressions are intentional — these are optional heavy dependencies that should never be loaded unless the user explicitly instantiates the splitter class - The regression test uses a subprocess for proper isolation (the test file itself imports `langchain_text_splitters` at the top, so `sys.modules` checks within the same process would not reflect a clean import state) Fixes #35437. > **AI disclaimer:** This PR was developed with assistance from Claude Code (Anthropic AI). --------- Co-authored-by: AshwathB-debug <ashwathbalaji04@gmail.com> Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com> Co-authored-by: Mason Daugherty <github@mdrxy.com>