gh-151526: Add csv writer tests for quote style edge cases by doma17 · Pull Request #151527 · python/cpython

Adds focused csv.writer coverage for QUOTE_STRINGS and QUOTE_NOTNULL.

The existing test_csv coverage already checks basic output for these quote styles. This adds narrower edge-case coverage for:

• rejecting quotechar=None when those quote styles enable quoting
• preserving quote/escape handling with escapechar and doublequote=False

This helps lock down behavior around the newer quoting modes and gives alternative implementations more precise regression coverage.

Testing:

• ./python.exe -m test test_csv -v
• ./python.exe -m test test_csv -q

• Issue: Add csv writer tests for QUOTE_STRINGS and QUOTE_NOTNULL edge cases #151526