2021-09-10 10:44:22 +12:00

108 lines
3.2 KiB
Rust

use crate::prelude::*;
use nu_engine::WholeStreamCommand;
use nu_errors::ShellError;
use nu_protocol::{
dataframe::{Column, NuDataFrame},
Signature, SyntaxShape, UntaggedValue, Value,
};
use nu_source::Tagged;
use super::utils::parse_polars_error;
pub struct DataFrame;
impl WholeStreamCommand for DataFrame {
fn name(&self) -> &str {
"dataframe with-column"
}
fn usage(&self) -> &str {
"[DataFrame] Adds a series to the dataframe"
}
fn signature(&self) -> Signature {
Signature::build("dataframe with-column")
.required("series", SyntaxShape::Any, "series to be added")
.required_named("name", SyntaxShape::String, "column name", Some('n'))
}
fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
command(args)
}
fn examples(&self) -> Vec<Example> {
vec![Example {
description: "Adds a series to the dataframe",
example:
"[[a b]; [1 2] [3 4]] | dataframe to-df | dataframe with-column ([5 6] | dataframe to-df) --name c",
result: Some(vec![NuDataFrame::try_from_columns(
vec![
Column::new(
"a".to_string(),
vec![
UntaggedValue::int(1).into(),
UntaggedValue::int(3).into(),
],
),
Column::new(
"b".to_string(),
vec![
UntaggedValue::int(2).into(),
UntaggedValue::int(4).into(),
],
),
Column::new(
"c".to_string(),
vec![
UntaggedValue::int(5).into(),
UntaggedValue::int(6).into(),
],
),
],
&Span::default(),
)
.expect("simple df for test should not fail")
.into_value(Tag::default())]),
}]
}
}
fn command(mut args: CommandArgs) -> Result<OutputStream, ShellError> {
let tag = args.call_info.name_tag.clone();
let value: Value = args.req(0)?;
let name: Tagged<String> = args.req_named("name")?;
let df = match value.value {
UntaggedValue::DataFrame(df) => Ok(df),
_ => Err(ShellError::labeled_error(
"Incorrect type",
"can only add a series to a dataframe",
value.tag.span,
)),
}?;
let mut series = df.as_series(&value.tag.span)?;
let series = series.rename(&name.item).clone();
let (mut df, _) = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
df.as_mut()
.with_column(series)
.map_err(|e| parse_polars_error::<&str>(&e, &tag.span, None))?;
Ok(OutputStream::one(df.into_value(tag)))
}
#[cfg(test)]
mod tests {
use super::DataFrame;
use super::ShellError;
#[test]
fn examples_work_as_expected() -> Result<(), ShellError> {
use crate::examples::test_dataframe as test_examples;
test_examples(DataFrame {})
}
}