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42 lines
1.1 KiB
42 lines
1.1 KiB
use polars::frame::DataFrame;
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use polars::prelude::*;
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use std::fs;
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use std::io;
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use std::io::Read;
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/// Read CSV format from stdin and return a Polars DataFrame
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pub fn load_csv_from_stdin() -> DataFrame {
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let mut buffer = String::new();
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let _res: () = match io::stdin().read_to_string(&mut buffer) {
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Ok(_ok) => (),
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Err(_e) => (),
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};
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let cursor = io::Cursor::new(buffer.as_bytes());
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let df = match CsvReader::new(cursor).finish() {
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Ok(df) => df,
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Err(_e) => DataFrame::default(),
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};
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df
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}
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/// Take a Polars Dataframe and write it as CSV to stdout
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pub fn dump_csv_to_stdout(df: &mut DataFrame) {
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let _res: () = match CsvWriter::new(io::stdout().lock()).finish(df) {
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Ok(_ok) => (),
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Err(_e) => (),
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};
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}
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/// Read parquet and return a Polars DataFrame
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pub fn read_parquet(path: String) -> DataFrame {
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let file = fs::File::open(path).expect("Could not open file");
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let df = match ParquetReader::new(file).finish() {
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Ok(df) => df,
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Err(e) => {
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eprintln!("{e}");
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DataFrame::default()
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}
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};
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df
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}
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