Struct JsonWriter

pub struct JsonWriter<W: Write> { /* private fields */ }

Available on crate feature json only.

Writes a DataFrame to JSON.

Under the hood, this uses arrow2::io::json. arrow2 generally serializes types that are not JSON primitives, such as Date and DateTime, as their Display-formatted versions. For instance, a (naive) DateTime column is formatted as the String "yyyy-mm-dd HH:MM:SS". To control how non-primitive columns are serialized, convert them to String or another primitive type before serializing.

Implementations

impl<W: Write> JsonWriter<W>

pub fn with_json_format(self, format: JsonFormat) -> Self

Trait Implementations

impl<W> SerWriter<W> for JsonWriter<W>

where W: Write,

fn new(buffer: W) -> Self

Create a new JsonWriter writing to buffer with format JsonFormat::JsonLines. To specify a different format, use e.g., JsonWriter::new(buffer).with_json_format(JsonFormat::Json).

fn finish(&mut self, df: &mut DataFrame) -> PolarsResult<()>