nushell/crates/nu-command/src/dataframe/eager/dummies.rs

142 lines
4.7 KiB
Rust

use super::super::values::{Column, NuDataFrame};
use nu_protocol::{
ast::Call,
engine::{Command, EngineState, Stack},
Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
};
use polars::prelude::DataFrameOps;
#[derive(Clone)]
pub struct Dummies;
impl Command for Dummies {
fn name(&self) -> &str {
"dummies"
}
fn usage(&self) -> &str {
"Creates a new dataframe with dummy variables"
}
fn signature(&self) -> Signature {
Signature::build(self.name())
.input_type(Type::Custom("dataframe".into()))
.output_type(Type::Custom("dataframe".into()))
.category(Category::Custom("dataframe".into()))
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Create new dataframe with dummy variables from a dataframe",
example: "[[a b]; [1 2] [3 4]] | into df | dummies",
result: Some(
NuDataFrame::try_from_columns(vec![
Column::new(
"a_1".to_string(),
vec![Value::test_int(1), Value::test_int(0)],
),
Column::new(
"a_3".to_string(),
vec![Value::test_int(0), Value::test_int(1)],
),
Column::new(
"b_2".to_string(),
vec![Value::test_int(1), Value::test_int(0)],
),
Column::new(
"b_4".to_string(),
vec![Value::test_int(0), Value::test_int(1)],
),
])
.expect("simple df for test should not fail")
.into_value(Span::test_data()),
),
},
Example {
description: "Create new dataframe with dummy variables from a series",
example: "[1 2 2 3 3] | into df | dummies",
result: Some(
NuDataFrame::try_from_columns(vec![
Column::new(
"0_1".to_string(),
vec![
Value::test_int(1),
Value::test_int(0),
Value::test_int(0),
Value::test_int(0),
Value::test_int(0),
],
),
Column::new(
"0_2".to_string(),
vec![
Value::test_int(0),
Value::test_int(1),
Value::test_int(1),
Value::test_int(0),
Value::test_int(0),
],
),
Column::new(
"0_3".to_string(),
vec![
Value::test_int(0),
Value::test_int(0),
Value::test_int(0),
Value::test_int(1),
Value::test_int(1),
],
),
])
.expect("simple df for test should not fail")
.into_value(Span::test_data()),
),
},
]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
command(engine_state, stack, call, input)
}
}
fn command(
_engine_state: &EngineState,
_stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let df = NuDataFrame::try_from_pipeline(input, call.head)?;
df.as_ref()
.to_dummies()
.map_err(|e| {
ShellError::GenericError(
"Error calculating dummies".into(),
e.to_string(),
Some(call.head),
Some("The only allowed column types for dummies are String or Int".into()),
Vec::new(),
)
})
.map(|df| PipelineData::Value(NuDataFrame::dataframe_into_value(df, call.head), None))
}
#[cfg(test)]
mod test {
use super::super::super::test_dataframe::test_dataframe;
use super::*;
#[test]
fn test_examples() {
test_dataframe(vec![Box::new(Dummies {})])
}
}