Fix Rust examples.

Translate all the Python examples to Rust.

docs/source/_build/API_REFERENCE_LINKS.yml

@@ -38,6 +38,9 @@ python:
   Expr.list:
     name: "list namespace"
     link: https://docs.pola.rs/api/python/stable/reference/expressions/list.html
+  Expr.str:
+    name: "str namespace"
+    link: https://docs.pola.rs/api/python/stable/reference/expressions/string.html
   element: https://docs.pola.rs/api/python/stable/reference/expressions/api/polars.element.html
   all: https://docs.pola.rs/api/python/stable/reference/expressions/api/polars.all.html
   exclude: https://docs.pola.rs/api/python/stable/reference/expressions/api/polars.exclude.html
@@ -156,6 +159,7 @@ python:
   Expr.name:
     name: "name namespace"
     link: https://docs.pola.rs/api/python/stable/reference/expressions/name.html
+  round: https://docs.pola.rs/api/python/stable/reference/expressions/api/polars.Expr.round.html#polars.Expr.round
 
 rust:
   DataFrame: https://docs.pola.rs/api/rust/dev/polars/frame/struct.DataFrame.html
@@ -293,7 +297,10 @@ rust:
   n_unique: https://docs.pola.rs/api/rust/dev/polars_lazy/dsl/enum.Expr.html#method.n_unique
   null_count: https://docs.pola.rs/api/rust/dev/polars_lazy/dsl/enum.Expr.html#method.null_count
   interpolate: https://docs.pola.rs/api/rust/dev/polars_lazy/dsl/enum.Expr.html#method.interpolate
-  is_between: https://github.com/pola-rs/polars/issues/11285
+  is_between:
+    name: is_between
+    link: https://docs.pola.rs/api/rust/dev/polars/prelude/enum.Expr.html#method.is_between
+    feature_flags: [is_between]
   is_duplicated: https://docs.pola.rs/api/rust/dev/polars_lazy/dsl/enum.Expr.html#method.is_duplicated
   is_null: https://docs.pola.rs/api/rust/dev/polars/prelude/enum.Expr.html#method.is_null
   value_counts:
@@ -304,6 +311,10 @@ rust:
   Expr.list:
     name: "list namespace"
     link: https://docs.pola.rs/api/rust/dev/polars_lazy/dsl/struct.ListNameSpace.html
+  Expr.str:
+    name: "str namespace"
+    link: https://docs.pola.rs/api/rust/dev/polars/prelude/trait.StringNameSpaceImpl.html
+    feature_flags: [strings]
   Series.arr: https://docs.pola.rs/api/rust/dev/polars_lazy/dsl/struct.ArrayNameSpace.html
 
   date_range:
@@ -395,3 +406,7 @@ rust:
     name: "dt namespace"
     link: https://docs.pola.rs/api/rust/dev/polars_lazy/dsl/dt/struct.DateLikeNameSpace.html
     feature_flags: [temporal]
+  round:
+    name: "round"
+    link: https://docs.pola.rs/api/rust/dev/polars/prelude/enum.Expr.html#method.round
+    feature_flags: [round_series]

docs/source/src/python/user-guide/getting-started/expressions.py

@@ -28,7 +28,7 @@
 # --8<-- [start:select]
 result = df.select(
     pl.col("name"),
-    pl.col("birthdate").dt.year().alias("birth year"),
+    pl.col("birthdate").dt.year().alias("birth_year"),
     (pl.col("weight") / (pl.col("height") ** 2)).alias("bmi"),
 )
 print(result)
@@ -37,15 +37,15 @@
 # --8<-- [start:expression-expansion]
 result = df.select(
     pl.col("name"),
-    (pl.col("weight", "height") * 0.95).round(2).name.suffix(" - 5%"),
+    (pl.col("weight", "height") * 0.95).round(2).name.suffix("-5%"),
 )
 print(result)
 # --8<-- [end:expression-expansion]
 
 # --8<-- [start:with_columns]
 result = df.with_columns(
-    pl.col("birthdate").dt.year().alias("birth year"),
-    (pl.col("weight") / (pl.col("height") ** 2)).alias("bmi"),
+    birth_year=pl.col("birthdate").dt.year(),
+    bmi=pl.col("weight") / (pl.col("height") ** 2),
 )
 print(result)
 # --8<-- [end:with_columns]
@@ -76,8 +76,8 @@
     (pl.col("birthdate").dt.year() // 10 * 10).alias("decade"),
     maintain_order=True,
 ).agg(
-    pl.len().alias("sample size"),
-    pl.col("weight").mean().round(2).alias("avg weight"),
+    pl.len().alias("sample_size"),
+    pl.col("weight").mean().round(2).alias("avg_weight"),
     pl.col("height").max().alias("tallest"),
 )
 print(result)
@@ -98,7 +98,7 @@
     )
     .agg(
         pl.col("name"),
-        pl.col("weight", "height").mean().round(2).name.prefix("avg "),
+        pl.col("weight", "height").mean().round(2).name.prefix("avg_"),
     )
 )
 print(result)
@@ -131,5 +131,5 @@
     }
 )
 
-print(df.vstack(df3))
+print(pl.concat([df, df3], how="vertical"))
 # --8<-- [end:concat]

docs/source/src/rust/Cargo.toml

@@ -28,10 +28,11 @@ required-features = ["polars/lazy", "polars/csv"]
 [[bin]]
 name = "user-guide-getting-started-expressions"
 path = "user-guide/getting-started/expressions.rs"
-required-features = ["polars/lazy"]
+required-features = ["polars/lazy", "polars/temporal", "polars/round_series", "polars/strings"]
 [[bin]]
 name = "user-guide-getting-started-joins"
 path = "user-guide/getting-started/joins.rs"
+required-features = ["polars/polars-ops"]
 [[bin]]
 name = "user-guide-getting-started-reading-writing"
 path = "user-guide/getting-started/reading-writing.rs"