[CSV] Add CSV dialect for RFC 4180 (original) (raw)

September 18, 2025, 7:32pm 1

RFC 4180 is a formalized standard for CSV files that has been around since 2005, and is pretty commonly referenced in API docs as a supported format (Even Microsoft’s own SQL Server API docs reference the RFC rather than calling it “excel csv”)

Currently, Python’s CSV module only provides excel and unix dialects, without explicitly providing much detail about what the actual dialect is.

To provide clarity to Python CSV stdlib users, I propose we add a new dialect “rfc4180” that explicitly implements RFC 4180. In practice, this appears to be identical to the existing excel dialect, however aliasing it as such will make it more clear to the user which standard is being followed.