polars.LazyFrame.sink_ndjson#
- LazyFrame.sink_ndjson(
- path: str | Path,
- *,
- maintain_order: bool = True,
- type_coercion: bool = True,
- predicate_pushdown: bool = True,
- projection_pushdown: bool = True,
- simplify_expression: bool = True,
- slice_pushdown: bool = True,
- no_optimization: bool = False,
Evaluate the query in streaming mode and write to an NDJSON file.
Warning
Streaming mode is considered unstable. It may be changed at any point without it being considered a breaking change.
This allows streaming results that are larger than RAM to be written to disk.
- Parameters:
- path
File path to which the file should be written.
- maintain_order
Maintain the order in which data is processed. Setting this to
Falsewill be slightly faster.- type_coercion
Do type coercion optimization.
- predicate_pushdown
Do predicate pushdown optimization.
- projection_pushdown
Do projection pushdown optimization.
- simplify_expression
Run simplify expressions optimization.
- slice_pushdown
Slice pushdown optimization.
- no_optimization
Turn off (certain) optimizations.
- Returns:
- DataFrame
Examples
>>> lf = pl.scan_csv("/path/to/my_larger_than_ram_file.csv") >>> lf.sink_ndjson("out.ndjson")