nushell/crates/nu-command/src/dataframe/eager/rename.rs
Fernando Herrera 6a35e6b7b6
Dataframe commands (#542)
* groupby object

* aggregate command

* eager commands

* rest of dataframe commands
2021-12-22 05:32:09 +11:00

95 lines
2.6 KiB
Rust

use nu_engine::CallExt;
use nu_protocol::{
ast::Call,
engine::{Command, EngineState, Stack},
Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
};
use super::super::values::{Column, NuDataFrame};
#[derive(Clone)]
pub struct RenameDF;
impl Command for RenameDF {
fn name(&self) -> &str {
"dfr rename-col"
}
fn usage(&self) -> &str {
"rename a dataframe column"
}
fn signature(&self) -> Signature {
Signature::build(self.name())
.required("from", SyntaxShape::String, "column name to be renamed")
.required("to", SyntaxShape::String, "new column name")
.category(Category::Custom("dataframe".into()))
}
fn examples(&self) -> Vec<Example> {
vec![Example {
description: "Renames a dataframe column",
example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr rename-col a a_new",
result: Some(
NuDataFrame::try_from_columns(vec![
Column::new(
"a_new".to_string(),
vec![Value::test_int(1), Value::test_int(3)],
),
Column::new(
"b".to_string(),
vec![Value::test_int(2), Value::test_int(4)],
),
])
.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 from: String = call.req(engine_state, stack, 0)?;
let to: String = call.req(engine_state, stack, 1)?;
let mut df = NuDataFrame::try_from_pipeline(input, call.head)?;
df.as_mut()
.rename(&from, &to)
.map_err(|e| {
ShellError::SpannedLabeledError("Error renaming".into(), e.to_string(), call.head)
})
.map(|df| {
PipelineData::Value(
NuDataFrame::dataframe_into_value(df.clone(), 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(RenameDF {})])
}
}