f1ee9113ac
* nuframe in its own type in UntaggedValue * Removed eager dataframe from enum * Dataframe created from list of values * Corrected order in dataframe columns * Returned tag from stream collection * Removed series from dataframe commands * Arithmetic operators * forced push * forced push * Replace all command * String commands * appending operations with dfs * Testing suite for dataframes * Unit test for dataframe commands * improved equality for dataframes
74 lines
2.1 KiB
Rust
74 lines
2.1 KiB
Rust
use crate::prelude::*;
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use nu_engine::WholeStreamCommand;
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use nu_errors::ShellError;
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use nu_protocol::{
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dataframe::{Column, NuDataFrame},
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Signature, SyntaxShape, UntaggedValue, Value,
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};
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use super::utils::{convert_columns, parse_polars_error};
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pub struct DataFrame;
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impl WholeStreamCommand for DataFrame {
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fn name(&self) -> &str {
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"dataframe get"
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}
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fn usage(&self) -> &str {
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"[DataFrame] Creates dataframe with the selected columns"
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}
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fn signature(&self) -> Signature {
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Signature::build("dataframe get").rest(SyntaxShape::Any, "column names to sort dataframe")
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}
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fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
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command(args)
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}
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fn examples(&self) -> Vec<Example> {
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vec![Example {
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description: "Creates dataframe with selected columns",
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example: "[[a b]; [1 2] [3 4]] | dataframe to-df | dataframe get a",
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result: Some(vec![NuDataFrame::try_from_columns(
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vec![Column::new(
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"a".to_string(),
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vec![UntaggedValue::int(1).into(), UntaggedValue::int(3).into()],
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)],
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&Span::default(),
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)
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.expect("simple df for test should not fail")
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.into_value(Tag::default())]),
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}]
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}
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}
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fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
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let tag = args.call_info.name_tag.clone();
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let columns: Vec<Value> = args.rest(0)?;
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let (col_string, col_span) = convert_columns(&columns, &tag)?;
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let (df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
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let res = df
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.as_ref()
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.select(&col_string)
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.map_err(|e| parse_polars_error::<&str>(&e, &col_span, None))?;
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Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
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}
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#[cfg(test)]
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mod tests {
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use super::DataFrame;
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use super::ShellError;
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#[test]
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fn examples_work_as_expected() -> Result<(), ShellError> {
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use crate::examples::test_dataframe as test_examples;
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test_examples(DataFrame {})
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}
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}
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