Polars update (#4875)

* update to polars 0.20

* add to date parser for series

crates/nu-command/src/dataframe/eager/describe.rs

@@ -162,7 +162,7 @@ fn command(
 
     let df = NuDataFrame::try_from_pipeline(input, call.head)?;
 
-    let names = ChunkedArray::<Utf8Type>::new_from_opt_slice("descriptor", &labels).into_series();
+    let names = ChunkedArray::<Utf8Type>::from_slice_options("descriptor", &labels).into_series();
 
     let head = std::iter::once(names);
 
@@ -235,7 +235,7 @@ fn command(
             descriptors.push(max);
 
             let name = format!("{} ({})", col.name(), col.dtype());
-            ChunkedArray::<Float64Type>::new_from_opt_slice(&name, &descriptors).into_series()
+            ChunkedArray::<Float64Type>::from_slice_options(&name, &descriptors).into_series()
         });
 
     let res = head.chain(tail).collect::<Vec<Series>>();

crates/nu-command/src/dataframe/eager/drop_duplicates.rs

@@ -4,6 +4,7 @@ use nu_protocol::{
     engine::{Command, EngineState, Stack},
     Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
 };
+use polars::prelude::DistinctKeepStrategy;
 
 use super::super::values::utils::convert_columns_string;
 use super::super::values::{Column, NuDataFrame};
@@ -28,6 +29,11 @@ impl Command for DropDuplicates {
                 "subset of columns to drop duplicates",
             )
             .switch("maintain", "maintain order", Some('m'))
+            .switch(
+                "last",
+                "keeps last duplicate value (by default keeps first)",
+                Some('l'),
+            )
             .category(Category::Custom("dataframe".into()))
     }
 
@@ -82,8 +88,14 @@ fn command(
 
     let subset_slice = subset.as_ref().map(|cols| &cols[..]);
 
+    let keep_strategy = if call.has_flag("last") {
+        DistinctKeepStrategy::Last
+    } else {
+        DistinctKeepStrategy::First
+    };
+
     df.as_ref()
-        .drop_duplicates(call.has_flag("maintain"), subset_slice)
+        .distinct(subset_slice, keep_strategy)
         .map_err(|e| {
             ShellError::SpannedLabeledError(
                 "Error dropping duplicates".into(),

crates/nu-command/src/dataframe/eager/to_csv.rs

@@ -71,7 +71,7 @@ fn command(
     let delimiter: Option<Spanned<String>> = call.get_flag(engine_state, stack, "delimiter")?;
     let no_header: bool = call.has_flag("no-header");
 
-    let df = NuDataFrame::try_from_pipeline(input, call.head)?;
+    let mut df = NuDataFrame::try_from_pipeline(input, call.head)?;
 
     let mut file = File::create(&file_name.item).map_err(|e| {
         ShellError::SpannedLabeledError(
@@ -109,7 +109,7 @@ fn command(
         }
     };
 
-    writer.finish(df.as_ref()).map_err(|e| {
+    writer.finish(df.as_mut()).map_err(|e| {
         ShellError::SpannedLabeledError(
             "Error writing to file".into(),
             e.to_string(),

crates/nu-command/src/dataframe/eager/to_parquet.rs

@@ -55,7 +55,7 @@ fn command(
 ) -> Result<PipelineData, ShellError> {
     let file_name: Spanned<PathBuf> = call.req(engine_state, stack, 0)?;
 
-    let df = NuDataFrame::try_from_pipeline(input, call.head)?;
+    let mut df = NuDataFrame::try_from_pipeline(input, call.head)?;
 
     let file = File::create(&file_name.item).map_err(|e| {
         ShellError::SpannedLabeledError(
@@ -65,7 +65,7 @@ fn command(
         )
     })?;
 
-    ParquetWriter::new(file).finish(df.as_ref()).map_err(|e| {
+    ParquetWriter::new(file).finish(df.as_mut()).map_err(|e| {
         ShellError::SpannedLabeledError("Error saving file".into(), e.to_string(), file_name.span)
     })?;