egolearner opened a new pull request, #49858: URL: https://github.com/apache/arrow/pull/49858
### Rationale for this change resolve #39961 ### What changes are included in this PR? When writing a dataset with CsvFileFormat configured with a custom ParseOptions delimiter (e.g. delimiter=">"), the output CSV still used the default "," delimiter. This was because: - C++ CsvFileFormat::DefaultWriteOptions() always created WriteOptions::Defaults() with delimiter=',', ignoring the parse_options.delimiter stored on the format object. - Python CsvFileFormat.make_write_options() unconditionally overwrote the C++ write options with a fresh WriteOptions(**kwargs), discarding any C++-side default that might have been set. Fix the C++ side by propagating parse_options.delimiter into the write options in DefaultWriteOptions(). Fix the Python side by reading the delimiter from the C++ default when the caller does not explicitly specify one, preventing the overwrite from losing the propagated value. ### Are these changes tested? Yes ### Are there any user-facing changes? No -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
