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

91 lines
2.4 KiB
Rust

use nu_protocol::{
ast::Call,
engine::{Command, EngineState, Stack},
Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
};
use crate::dataframe::values::Column;
use super::super::values::NuDataFrame;
#[derive(Clone)]
pub struct ShapeDF;
impl Command for ShapeDF {
fn name(&self) -> &str {
"shape"
}
fn usage(&self) -> &str {
"Shows column and row size for a dataframe"
}
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: "Shows row and column shape",
example: "[[a b]; [1 2] [3 4]] | into df | shape",
result: Some(
NuDataFrame::try_from_columns(vec![
Column::new("rows".to_string(), vec![Value::test_int(2)]),
Column::new("columns".to_string(), vec![Value::test_int(2)]),
])
.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)?;
let rows = Value::Int {
val: df.as_ref().height() as i64,
span: call.head,
};
let cols = Value::Int {
val: df.as_ref().width() as i64,
span: call.head,
};
let rows_col = Column::new("rows".to_string(), vec![rows]);
let cols_col = Column::new("columns".to_string(), vec![cols]);
NuDataFrame::try_from_columns(vec![rows_col, cols_col])
.map(|df| PipelineData::Value(df.into_value(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(ShapeDF {})])
}
}