Documentation and error handling around polars with-column --name (#14527)

The `--name` flag of `polars with-column` only works when used with an
eager dataframe. I will not work with lazy dataframes and it will not
work when used with expressions (which forces a conversion to a
lazyframe). This pull request adds better documentation to the flags and
errors messages when used in cases where it will not work.
This commit is contained in:
Jack Wright 2024-12-06 03:17:18 -08:00 committed by GitHub
parent 4c9078cccc
commit 81d68cd478
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@ -6,8 +6,8 @@ use crate::{
};
use nu_plugin::{EngineInterface, EvaluatedCall, PluginCommand};
use nu_protocol::{
Category, Example, LabeledError, PipelineData, ShellError, Signature, Span, SyntaxShape, Type,
Value,
Category, Example, LabeledError, PipelineData, ShellError, Signature, Span, Spanned,
SyntaxShape, Type, Value,
};
#[derive(Clone)]
@ -26,7 +26,7 @@ impl PluginCommand for WithColumn {
fn signature(&self) -> Signature {
Signature::build(self.name())
.named("name", SyntaxShape::String, "new column name", Some('n'))
.named("name", SyntaxShape::String, "New column name. For lazy dataframes and expressions syntax, use a `polars as` expression to name a column.", Some('n'))
.rest(
"series or expressions",
SyntaxShape::Any,
@ -138,6 +138,15 @@ fn command_eager(
let column_span = new_column.span();
if NuExpression::can_downcast(&new_column) {
if let Some(name) = call.get_flag::<Spanned<String>>("name")? {
return Err(ShellError::GenericError {
error: "Flag 'name' is unsuppored when used with expressions. Please use the `polars as` expression to name a column".into(),
msg: "".into(),
span: Some(name.span),
help: Some("Use a `polars as` expression to name a column".into()),
inner: vec![],
});
}
let vals: Vec<Value> = call.rest(0)?;
let value = Value::list(vals, call.head);
let expressions = NuExpression::extract_exprs(plugin, value)?;
@ -177,6 +186,16 @@ fn command_lazy(
call: &EvaluatedCall,
lazy: NuLazyFrame,
) -> Result<PipelineData, ShellError> {
if let Some(name) = call.get_flag::<Spanned<String>>("name")? {
return Err(ShellError::GenericError {
error: "Flag 'name' is unsuppored for lazy dataframes. Please use the `polars as` expression to name a column".into(),
msg: "".into(),
span: Some(name.span),
help: Some("Use a `polars as` expression to name a column".into()),
inner: vec![],
});
}
let vals: Vec<Value> = call.rest(0)?;
let value = Value::list(vals, call.head);
let expressions = NuExpression::extract_exprs(plugin, value)?;