pub fn data_extension(path: &Path) -> Option<String>Expand description
The extension that says what a file is, with any compression suffix walked past.
sales.csv.gz is a CSV: Path::extension answers gz, which is how it is stored
rather than what it holds. Anything deciding a format wants this one — two files
named .csv.gz and .json.gz agree on their extension and on nothing that
matters.
None when the name does not end in something datui reads.