writeCsvFile

void writeCsvFile(string path,  LazyFrame df,
       CsvWritePolicy policy =  CsvWritePolicy.init,
       size_t batchSize =  65_536)

@trusted

Writes a deferred frame to a CSV file incrementally: batches pull through the row-wise chain one at a time (the input never materialises), the header writes once, and each pull appends its rows. The temp-then-rename failure policy applies - a failed write never leaves a partial file.

Parameters

`path`	the destination path
`df`	the deferred frame
`policy`	the writing policy
`batchSize`	the pull width (blocking-fallback iteration)

Throws

DataFrameException on IO failure (the temp file removed

either way).