use crate::{
PolarsPlugin,
dataframe::values::{Column, NuDataFrame, NuExpression},
values::{CustomValueSupport, PolarsPluginObject, PolarsPluginType, cant_convert_err},
};
use nu_plugin::{EngineInterface, EvaluatedCall, PluginCommand};
use nu_protocol::{
Category, Example, LabeledError, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
};
#[derive(Clone)]
pub struct LazyFillNA;
impl PluginCommand for LazyFillNA {
type Plugin = PolarsPlugin;
fn name(&self) -> &str {
"polars fill-nan"
}
fn description(&self) -> &str {
"Replaces NaN values with the given expression."
}
fn signature(&self) -> Signature {
Signature::build(self.name())
.required(
"fill",
SyntaxShape::Any,
"Expression to use to fill the NAN values.",
)
.input_output_types(vec![
(
PolarsPluginType::NuDataFrame.into(),
PolarsPluginType::NuDataFrame.into(),
),
(
PolarsPluginType::NuLazyFrame.into(),
PolarsPluginType::NuLazyFrame.into(),
),
])
.category(Category::Custom("lazyframe".into()))
}
fn examples(&self) -> Vec<Example<'_>> {
vec![
Example {
description: "Fills the NaN values with 0",
example: "[1 2 NaN 3 NaN] | polars into-df | polars fill-nan 0",
result: Some(
NuDataFrame::try_from_columns(
vec![Column::new(
"0".to_string(),
vec![
Value::test_int(1),
Value::test_int(2),
Value::test_int(0),
Value::test_int(3),
Value::test_int(0),
],
)],
None,
Span::test_data(),
)
.expect("Df for test should not fail")
.into_value(Span::test_data()),
),
},
Example {
description: "Fills the NaN values of a whole dataframe",
example: "[[a b]; [0.2 1] [0.1 NaN]] | polars into-df | polars fill-nan 0",
result: Some(
NuDataFrame::try_from_columns(
vec![
Column::new(
"a".to_string(),
vec![Value::test_float(0.2), Value::test_float(0.1)],
),
Column::new(
"b".to_string(),
vec![Value::test_int(1), Value::test_int(0)],
),
],
None,
Span::test_data(),
)
.expect("Df for test should not fail")
.into_value(Span::test_data()),
),
},
]
}
fn run(
&self,
plugin: &Self::Plugin,
engine: &EngineInterface,
call: &EvaluatedCall,
mut input: PipelineData,
) -> Result<PipelineData, LabeledError> {
let fill: Value = call.req(0)?;
let metadata = input.take_metadata();
let value = input.into_value(call.head)?;
match PolarsPluginObject::try_from_value(plugin, &value)? {
PolarsPluginObject::NuDataFrame(df) => {
cmd_df(plugin, engine, call, df, fill, value.span())
}
PolarsPluginObject::NuLazyFrame(lazy) => cmd_df(
plugin,
engine,
call,
lazy.collect(value.span())?,
fill,
value.span(),
),
PolarsPluginObject::NuExpression(expr) => {
Ok(cmd_expr(plugin, engine, call, expr, fill)?)
}
_ => Err(cant_convert_err(
&value,
&[
PolarsPluginType::NuDataFrame,
PolarsPluginType::NuLazyFrame,
PolarsPluginType::NuExpression,
],
)),
}
.map_err(LabeledError::from)
.map(|pd| pd.set_metadata(metadata))
}
}
fn cmd_df(
plugin: &PolarsPlugin,
engine: &EngineInterface,
call: &EvaluatedCall,
frame: NuDataFrame,
fill: Value,
val_span: Span,
) -> Result<PipelineData, ShellError> {
let columns = frame.columns(val_span)?;
let dataframe = columns
.into_iter()
.map(|column| {
let column_name = column.name().to_string();
let values = column
.into_iter()
.map(|value| {
let span = value.span();
match value {
Value::Float { val, .. } => {
if val.is_nan() {
fill.clone()
} else {
value
}
}
Value::List { vals, .. } => {
NuDataFrame::fill_list_nan(vals, span, fill.clone())
}
_ => value,
}
})
.collect::<Vec<Value>>();
Column::new(column_name, values)
})
.collect::<Vec<Column>>();
let df = NuDataFrame::try_from_columns(dataframe, None, call.head)?;
df.to_pipeline_data(plugin, engine, call.head)
}
fn cmd_expr(
plugin: &PolarsPlugin,
engine: &EngineInterface,
call: &EvaluatedCall,
expr: NuExpression,
fill: Value,
) -> Result<PipelineData, ShellError> {
let fill = NuExpression::try_from_value(plugin, &fill)?.into_polars();
let expr: NuExpression = expr.into_polars().fill_nan(fill).into();
expr.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(&LazyFillNA)
}
}