nushell/crates/nu_plugin_polars/src/dataframe/series/shift.rs
Stefan Holderbach be6137d136
Fix clippy::wrong_self_convention in polars plugin (#12737)
Expected `into_` for `fn(self) -> T`
2024-05-02 19:31:51 +02:00

134 lines
3.8 KiB
Rust

use crate::{
dataframe::values::{NuExpression, NuLazyFrame},
values::{cant_convert_err, CustomValueSupport, PolarsPluginObject, PolarsPluginType},
PolarsPlugin,
};
use super::super::values::{Column, NuDataFrame};
use nu_plugin::{EngineInterface, EvaluatedCall, PluginCommand};
use nu_protocol::{
Category, Example, LabeledError, PipelineData, ShellError, Signature, Span, SyntaxShape, Type,
Value,
};
use polars_plan::prelude::lit;
#[derive(Clone)]
pub struct Shift;
impl PluginCommand for Shift {
type Plugin = PolarsPlugin;
fn name(&self) -> &str {
"polars shift"
}
fn usage(&self) -> &str {
"Shifts the values by a given period."
}
fn signature(&self) -> Signature {
Signature::build(self.name())
.required("period", SyntaxShape::Int, "shift period")
.named(
"fill",
SyntaxShape::Any,
"Expression used to fill the null values (lazy df)",
Some('f'),
)
.input_output_type(
Type::Custom("dataframe".into()),
Type::Custom("dataframe".into()),
)
.category(Category::Custom("dataframe or lazyframe".into()))
}
fn examples(&self) -> Vec<Example> {
vec![Example {
description: "Shifts the values by a given period",
example: "[1 2 2 3 3] | polars into-df | polars shift 2 | polars drop-nulls",
result: Some(
NuDataFrame::try_from_columns(
vec![Column::new(
"0".to_string(),
vec![Value::test_int(1), Value::test_int(2), Value::test_int(2)],
)],
None,
)
.expect("simple df for test should not fail")
.into_value(Span::test_data()),
),
}]
}
fn run(
&self,
plugin: &Self::Plugin,
engine: &EngineInterface,
call: &EvaluatedCall,
input: PipelineData,
) -> Result<PipelineData, LabeledError> {
let value = input.into_value(call.head);
match PolarsPluginObject::try_from_value(plugin, &value)? {
PolarsPluginObject::NuDataFrame(df) => command_eager(plugin, engine, call, df),
PolarsPluginObject::NuLazyFrame(lazy) => command_lazy(plugin, engine, call, lazy),
_ => Err(cant_convert_err(
&value,
&[
PolarsPluginType::NuDataFrame,
PolarsPluginType::NuLazyGroupBy,
],
)),
}
.map_err(LabeledError::from)
}
}
fn command_eager(
plugin: &PolarsPlugin,
engine: &EngineInterface,
call: &EvaluatedCall,
df: NuDataFrame,
) -> Result<PipelineData, ShellError> {
let period: i64 = call.req(0)?;
let series = df.as_series(call.head)?.shift(period);
let df = NuDataFrame::try_from_series_vec(vec![series], call.head)?;
df.to_pipeline_data(plugin, engine, call.head)
}
fn command_lazy(
plugin: &PolarsPlugin,
engine: &EngineInterface,
call: &EvaluatedCall,
lazy: NuLazyFrame,
) -> Result<PipelineData, ShellError> {
let shift: i64 = call.req(0)?;
let fill: Option<Value> = call.get_flag("fill")?;
let lazy = lazy.to_polars();
let lazy: NuLazyFrame = match fill {
Some(ref fill) => {
let expr = NuExpression::try_from_value(plugin, fill)?.into_polars();
lazy.shift_and_fill(lit(shift), expr).into()
}
None => lazy.shift(shift).into(),
};
lazy.to_pipeline_data(plugin, engine, call.head)
}
#[cfg(test)]
mod test {
use super::*;
use crate::test::test_polars_plugin_command;
#[test]
fn test_examples() -> Result<(), ShellError> {
test_polars_plugin_command(&Shift)
}
}