forked from extern/nushell
aa1cd7eba6
* Sample command * Join command with checks * More dataframes commands * Groupby and aggregate commands * Missing feature dataframe flag * Renamed file * New commands for dataframes * error parser and df reference * filter command for dataframes * removed name from nu_dataframe * commands to save to parquet and csv * polars new version * new dataframe commands * series type and print * Series basic arithmetics * Add new column to dataframe * Command names changed to nushell standard
71 lines
2.0 KiB
Rust
71 lines
2.0 KiB
Rust
use crate::prelude::*;
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use nu_engine::WholeStreamCommand;
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use nu_errors::ShellError;
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use nu_protocol::{dataframe::NuDataFrame, Signature, SyntaxShape, Value};
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use super::utils::{convert_columns, parse_polars_error};
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pub struct DataFrame;
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impl WholeStreamCommand for DataFrame {
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fn name(&self) -> &str {
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"pls drop"
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}
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fn usage(&self) -> &str {
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"Creates a new dataframe by dropping the selected columns"
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}
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fn signature(&self) -> Signature {
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Signature::build("pls drop").required(
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"columns",
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SyntaxShape::Table,
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"column names to be dropped",
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)
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}
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fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
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command(args)
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}
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fn examples(&self) -> Vec<Example> {
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vec![Example {
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description: "drop column a",
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example: "[[a b]; [1 2] [3 4]] | pls to-df | pls drop [a]",
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result: None,
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}]
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}
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}
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fn command(args: CommandArgs) -> Result<OutputStream, ShellError> {
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let tag = args.call_info.name_tag.clone();
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let mut args = args.evaluate_once()?;
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let columns: Vec<Value> = args.req(0)?;
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let (col_string, col_span) = convert_columns(&columns, &tag)?;
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let df = NuDataFrame::try_from_stream(&mut args.input, &tag.span)?;
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let new_df = match col_string.iter().next() {
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Some(col) => df
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.as_ref()
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.drop(col)
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.map_err(|e| parse_polars_error::<&str>(&e, &col_span, None)),
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None => Err(ShellError::labeled_error(
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"Empty names list",
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"No column names where found",
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&col_span,
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)),
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}?;
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// If there are more columns in the drop selection list, these
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// are added from the resulting dataframe
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let res = col_string.iter().skip(1).try_fold(new_df, |new_df, col| {
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new_df
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.drop(col)
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.map_err(|e| parse_polars_error::<&str>(&e, &col_span, None))
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})?;
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Ok(OutputStream::one(NuDataFrame::dataframe_to_value(res, tag)))
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}
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