# Description Replace `.to_string()` used in `GenericError` with `.into()` as `.into()` seems more popular Replace `Vec::new()` used in `GenericError` with `vec![]` as `vec![]` seems more popular (There are so, so many)
187 lines
5.7 KiB
Rust
187 lines
5.7 KiB
Rust
use super::super::values::{Column, NuDataFrame};
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use nu_engine::CallExt;
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use nu_protocol::{
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ast::Call,
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engine::{Command, EngineState, Stack},
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Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Type,
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Value,
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};
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use polars::prelude::{DataType, Duration, IntoSeries, RollingOptionsImpl, SeriesOpsTime};
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enum RollType {
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Min,
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Max,
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Sum,
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Mean,
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}
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impl RollType {
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fn from_str(roll_type: &str, span: Span) -> Result<Self, ShellError> {
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match roll_type {
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"min" => Ok(Self::Min),
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"max" => Ok(Self::Max),
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"sum" => Ok(Self::Sum),
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"mean" => Ok(Self::Mean),
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_ => Err(ShellError::GenericError {
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error: "Wrong operation".into(),
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msg: "Operation not valid for cumulative".into(),
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span: Some(span),
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help: Some("Allowed values: min, max, sum, mean".into()),
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inner: vec![],
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}),
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}
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}
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fn to_str(&self) -> &'static str {
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match self {
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RollType::Min => "rolling_min",
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RollType::Max => "rolling_max",
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RollType::Sum => "rolling_sum",
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RollType::Mean => "rolling_mean",
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}
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}
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}
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#[derive(Clone)]
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pub struct Rolling;
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impl Command for Rolling {
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fn name(&self) -> &str {
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"dfr rolling"
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}
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fn usage(&self) -> &str {
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"Rolling calculation for a series."
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}
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fn signature(&self) -> Signature {
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Signature::build(self.name())
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.required("type", SyntaxShape::String, "rolling operation")
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.required("window", SyntaxShape::Int, "Window size for rolling")
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.input_output_type(
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Type::Custom("dataframe".into()),
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Type::Custom("dataframe".into()),
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)
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.category(Category::Custom("dataframe".into()))
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}
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fn examples(&self) -> Vec<Example> {
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vec![
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Example {
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description: "Rolling sum for a series",
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example: "[1 2 3 4 5] | dfr into-df | dfr rolling sum 2 | dfr drop-nulls",
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result: Some(
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NuDataFrame::try_from_columns(vec![Column::new(
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"0_rolling_sum".to_string(),
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vec![
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Value::test_int(3),
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Value::test_int(5),
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Value::test_int(7),
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Value::test_int(9),
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],
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)])
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.expect("simple df for test should not fail")
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.into_value(Span::test_data()),
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),
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},
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Example {
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description: "Rolling max for a series",
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example: "[1 2 3 4 5] | dfr into-df | dfr rolling max 2 | dfr drop-nulls",
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result: Some(
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NuDataFrame::try_from_columns(vec![Column::new(
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"0_rolling_max".to_string(),
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vec![
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Value::test_int(2),
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Value::test_int(3),
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Value::test_int(4),
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Value::test_int(5),
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],
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)])
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.expect("simple df for test should not fail")
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.into_value(Span::test_data()),
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),
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},
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]
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}
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fn run(
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&self,
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engine_state: &EngineState,
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stack: &mut Stack,
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call: &Call,
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input: PipelineData,
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) -> Result<PipelineData, ShellError> {
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command(engine_state, stack, call, input)
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}
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}
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fn command(
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engine_state: &EngineState,
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stack: &mut Stack,
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call: &Call,
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input: PipelineData,
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) -> Result<PipelineData, ShellError> {
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let roll_type: Spanned<String> = call.req(engine_state, stack, 0)?;
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let window_size: i64 = call.req(engine_state, stack, 1)?;
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let df = NuDataFrame::try_from_pipeline(input, call.head)?;
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let series = df.as_series(call.head)?;
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if let DataType::Object(_) = series.dtype() {
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return Err(ShellError::GenericError {
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error: "Found object series".into(),
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msg: "Series of type object cannot be used for rolling operation".into(),
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span: Some(call.head),
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help: None,
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inner: vec![],
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});
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}
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let roll_type = RollType::from_str(&roll_type.item, roll_type.span)?;
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let rolling_opts = RollingOptionsImpl {
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window_size: Duration::new(window_size),
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min_periods: window_size as usize,
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weights: None,
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center: false,
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by: None,
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closed_window: None,
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tu: None,
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tz: None,
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fn_params: None,
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};
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let res = match roll_type {
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RollType::Max => series.rolling_max(rolling_opts),
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RollType::Min => series.rolling_min(rolling_opts),
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RollType::Sum => series.rolling_sum(rolling_opts),
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RollType::Mean => series.rolling_mean(rolling_opts),
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};
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let mut res = res.map_err(|e| ShellError::GenericError {
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error: "Error calculating rolling values".into(),
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msg: e.to_string(),
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span: Some(call.head),
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help: None,
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inner: vec![],
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})?;
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let name = format!("{}_{}", series.name(), roll_type.to_str());
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res.rename(&name);
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NuDataFrame::try_from_series(vec![res.into_series()], call.head)
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.map(|df| PipelineData::Value(NuDataFrame::into_value(df, call.head), None))
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}
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#[cfg(test)]
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mod test {
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use super::super::super::eager::DropNulls;
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use super::super::super::test_dataframe::test_dataframe;
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use super::*;
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#[test]
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fn test_examples() {
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test_dataframe(vec![Box::new(Rolling {}), Box::new(DropNulls {})])
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}
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}
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