If both parties implement RFC 4180 and use a consistent character set encoding t...

senknvd · 2024-03-26T00:48:43 1711414123

I don't think RFC 4180 differentiates between an empty string and a null value. As long as you add a check that all string columns are free of empty values before writing you should be good.

I think in polars it's

    df.filter(pl.col(pl.Utf8).str.len_bytes() == 0).shape[0] == 0

although there's probably a better way to write this.

nradov · 2024-03-26T01:36:03 1711416963

Well I would consider differentiation between empty string versus null as simply being out of scope for CSV rather than undefined behavior. It was never intended as a complete database dump format.

thayne · 2024-03-26T01:45:13 1711417513

And the application doesn't try to convert the cells into non-string data types like numbers, dates, etc.

nradov · 2024-03-26T01:54:45 1711418085

Converting strings into other data types is out of scope for CSV, not really undefined behavior. The type conversions happen at a later stage of the import process.

thayne · 2024-03-26T03:17:46 1711423066

It's out of scope for the RFC, but it could still be undefined behavior for the import/export process.