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use super::explode::explode;
use crate::dataframe::values::{Column, NuDataFrame};
use nu_engine::command_prelude::*;
#[derive(Clone)]
pub struct LazyFlatten;
impl Command for LazyFlatten {
fn name(&self) -> &str {
"dfr flatten"
}
fn usage(&self) -> &str {
"An alias for dfr explode."
}
fn signature(&self) -> Signature {
Signature::build(self.name())
.rest(
"columns",
SyntaxShape::String,
"columns to flatten, only applicable for dataframes",
)
.input_output_types(vec![
(
Type::Custom("expression".into()),
Type::Custom("expression".into()),
),
(
Type::Custom("dataframe".into()),
Type::Custom("dataframe".into()),
),
])
.category(Category::Custom("lazyframe".into()))
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Flatten the specified dataframe",
example: "[[id name hobbies]; [1 Mercy [Cycling Knitting]] [2 Bob [Skiing Football]]] | dfr into-df | dfr flatten hobbies | dfr collect",
result: Some(
NuDataFrame::try_from_columns(vec![
Column::new(
"id".to_string(),
vec![
Value::test_int(1),
Value::test_int(1),
Value::test_int(2),
Value::test_int(2),
]),
Column::new(
"name".to_string(),
vec![
Value::test_string("Mercy"),
Value::test_string("Mercy"),
Value::test_string("Bob"),
Value::test_string("Bob"),
]),
Column::new(
"hobbies".to_string(),
vec![
Value::test_string("Cycling"),
Value::test_string("Knitting"),
Value::test_string("Skiing"),
Value::test_string("Football"),
]),
], None).expect("simple df for test should not fail")
.into_value(Span::test_data()),
)
},
Example {
description: "Select a column and flatten the values",
example: "[[id name hobbies]; [1 Mercy [Cycling Knitting]] [2 Bob [Skiing Football]]] | dfr into-df | dfr select (dfr col hobbies | dfr flatten)",
result: Some(
NuDataFrame::try_from_columns(vec![
Column::new(
"hobbies".to_string(),
vec![
Value::test_string("Cycling"),
Value::test_string("Knitting"),
Value::test_string("Skiing"),
Value::test_string("Football"),
]),
], None).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> {
explode(call, input)
}
}
#[cfg(test)]
mod test {
use super::super::super::test_dataframe::{build_test_engine_state, test_dataframe_example};
use super::*;
use crate::dataframe::lazy::aggregate::LazyAggregate;
use crate::dataframe::lazy::groupby::ToLazyGroupBy;
#[test]
fn test_examples_dataframe() {
let mut engine_state = build_test_engine_state(vec![Box::new(LazyFlatten {})]);
test_dataframe_example(&mut engine_state, &LazyFlatten.examples()[0]);
}
#[ignore]
#[test]
fn test_examples_expression() {
let mut engine_state = build_test_engine_state(vec![
Box::new(LazyFlatten {}),
Box::new(LazyAggregate {}),
Box::new(ToLazyGroupBy {}),
]);
test_dataframe_example(&mut engine_state, &LazyFlatten.examples()[1]);
}
}
|
