Add NULL and empty string handling documentation#643
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laughingman7743 merged 1 commit intomasterfrom Jan 6, 2026
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Add comprehensive documentation explaining NULL and empty string behavior across different cursor types: - Default Cursor and DictCursor properly distinguish NULL from empty string - PandasCursor with CSV treats both as NaN, but works correctly with unload - ArrowCursor with CSV treats both as empty string, but works correctly with unload - PolarsCursor properly distinguishes in both CSV and Parquet modes - S3FSCursor properly distinguishes using custom AthenaCSVReader This documentation helps users understand the CSV format limitation and provides workarounds (unload option, PolarsCursor, S3FSCursor) for applications that need to distinguish NULL from empty string values. Unify test method names to `test_null_vs_empty_string` across all cursor types: - TestCursor.test_null_vs_empty_string - TestDictCursor.test_null_vs_empty_string - TestPandasCursor.test_null_vs_empty_string (renamed from test_empty_and_null_string) - TestArrowCursor.test_null_vs_empty_string - TestPolarsCursor.test_null_vs_empty_string - TestS3FSCursor.test_null_vs_empty_string (consolidated with parametrize) Closes #118 Closes #148 Closes #168 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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Summary
docs/null_handling.rst) explaining NULL and empty string behavior across different cursor types,,) and empty string (,"",) are represented differentlyunload=Trueoption,PolarsCursor, orS3FSCursortest_null_vs_empty_stringacross all cursor typesCursor Behavior Summary
''None''NoneNaNNaN''None''''''null''null''NoneNoneNoneS3FSCursor CSV Readers
S3FSCursorsupports two CSV readers:NoneTest plan
make chk- all quality checks passmake docsto verify rst file renders correctlyCloses #118
Closes #148
Closes #168
🤖 Generated with Claude Code