bkietz commented on pull request #9130: URL: https://github.com/apache/arrow/pull/9130#issuecomment-760312991
@pitrou The dictionaries are [a feature inspired by ParquetDataset](https://github.com/apache/arrow/pull/7536#issuecomment-649500017): it's useful for each partition expression to contain the dictionary of all unique values that field could take. They are only required when parsing paths. When constructing a Partitioning from a factory (inferring fields from a vector of paths) the dictionaries are assembled automatically. However if the Partitioning is being directly constructed then the dictionaries must be explicitly specified. @jorisvandenbossche I'll add a binding for `max_partitions` to python ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
