Version-scope correction: 2026-10-05 UTC
Verified execution scope: CPython 3.12.14 / Linux only.
No production split_csv.py or expected CSV modification.
Two additional tests directly construct quoted isolated CR and CRLF memo inputs independently of writer behavior.
Full suite: 48 tests, exit_code 0, OK; see logs/10_cr_crlf_scope_tests.txt and final full-suite log.
Other Python versions are not claimed compatible. Run all provided tests, particularly isolated CR and CRLF field preservation, before use.
Official CPython v3.10.19 and v3.12.14 Modules/_csv.c join_append_data differ in explicitly treating CR/LF as writer-special characters.
Source comparison is source inspection, not execution of CPython 3.10.19.
https://raw.githubusercontent.com/python/cpython/v3.10.19/Modules/_csv.c
https://raw.githubusercontent.com/python/cpython/v3.12.14/Modules/_csv.c
