remove mean_as_series from series_trait

polars/polars-core/src/chunked_array/categorical/merge.rs

@@ -71,13 +71,13 @@ impl CategoricalChunked {
 }
 
 #[cfg(test)]
+#[cfg(feature = "single_thread")]
 mod test {
     use super::*;
     use crate::chunked_array::categorical::CategoricalChunkedBuilder;
     use crate::{reset_string_cache, toggle_string_cache};
 
     #[test]
-    #[cfg(feature = "single_thread")]
     fn test_merge_rev_map() {
         reset_string_cache();
         toggle_string_cache(true);

polars/polars-core/src/chunked_array/ops/aggregate.rs

@@ -24,10 +24,6 @@ pub trait ChunkAggSeries {
     fn min_as_series(&self) -> Series {
         unimplemented!()
     }
-    /// Get the mean of the ChunkedArray as a new Series of length 1.
-    fn mean_as_series(&self) -> Series {
-        unimplemented!()
-    }
     /// Get the product of the ChunkedArray as a new Series of length 1.
     fn prod_as_series(&self) -> Series {
         unimplemented!()
@@ -522,10 +518,6 @@ where
         ca.rename(self.name());
         ca.into_series()
     }
-    fn mean_as_series(&self) -> Series {
-        let val = [self.mean()];
-        Series::new(self.name(), val)
-    }
 
     fn prod_as_series(&self) -> Series {
         let mut prod = None;
@@ -777,9 +769,6 @@ impl ChunkAggSeries for BooleanChunked {
         ca.rename(self.name());
         ca.into_series()
     }
-    fn mean_as_series(&self) -> Series {
-        BooleanChunked::full_null(self.name(), 1).into_series()
-    }
 }
 
 macro_rules! one_null_utf8 {
@@ -800,9 +789,6 @@ impl ChunkAggSeries for Utf8Chunked {
     fn min_as_series(&self) -> Series {
         one_null_utf8!(self)
     }
-    fn mean_as_series(&self) -> Series {
-        one_null_utf8!(self)
-    }
 }
 
 #[cfg(feature = "dtype-categorical")]
@@ -826,9 +812,6 @@ impl ChunkAggSeries for ListChunked {
     fn min_as_series(&self) -> Series {
         one_null_list!(self)
     }
-    fn mean_as_series(&self) -> Series {
-        one_null_list!(self)
-    }
 }
 
 #[cfg(feature = "object")]
@@ -969,11 +952,22 @@ mod test {
         let ca = Float32Chunked::new("", &[Some(1.0), Some(2.0), None]);
         assert_eq!(ca.mean().unwrap(), 1.5);
         // all mean_as_series are cast to f64.
-        assert_eq!(ca.mean_as_series().f64().unwrap().get(0).unwrap(), 1.5);
+        assert_eq!(
+            ca.into_series()
+                .mean_as_series()
+                .f64()
+                .unwrap()
+                .get(0)
+                .unwrap(),
+            1.5
+        );
         // all null values case
         let ca = Float32Chunked::full_null("", 3);
         assert_eq!(ca.mean(), None);
-        assert_eq!(ca.mean_as_series().f64().unwrap().get(0), None);
+        assert_eq!(
+            ca.into_series().mean_as_series().f64().unwrap().get(0),
+            None
+        );
     }
 
     #[test]

polars/polars-core/src/frame/groupby/mod.rs

@@ -1470,10 +1470,10 @@ mod test {
             let ca = UInt32Chunked::new("", slice);
             let split = split_ca(&ca, 4).unwrap();
 
-            let mut a = groupby(ca.into_iter(), true).into_idx();
+            let a = groupby(ca.into_iter(), true).into_idx();
 
             let keys = split.iter().map(|ca| ca.cont_slice().unwrap()).collect();
-            let mut b = groupby_threaded_num(keys, 0, split.len() as u64, true).into_idx();
+            let b = groupby_threaded_num(keys, 0, split.len() as u64, true).into_idx();
 
             assert_eq!(a, b);
         }

polars/polars-core/src/prelude.rs

@@ -19,7 +19,7 @@ pub use crate::{
     df,
     error::{PolarsError, Result},
     frame::{groupby::GroupsProxy, hash_join::JoinType, *},
-    named_from::NamedFrom,
+    named_from::{NamedFrom, NamedFromOwned},
     series::{
         arithmetic::{LhsNumOps, NumOpsDispatch},
         IntoSeries, Series, SeriesTrait,

polars/polars-core/src/series/implementations/boolean.rs

@@ -323,9 +323,6 @@ impl SeriesTrait for SeriesWrap<BooleanChunked> {
     fn min_as_series(&self) -> Series {
         ChunkAggSeries::min_as_series(&self.0)
     }
-    fn mean_as_series(&self) -> Series {
-        ChunkAggSeries::mean_as_series(&self.0)
-    }
     fn median_as_series(&self) -> Series {
         QuantileAggSeries::median_as_series(&self.0)
     }

polars/polars-core/src/series/implementations/categorical.rs

@@ -302,9 +302,6 @@ impl SeriesTrait for SeriesWrap<CategoricalChunked> {
     fn min_as_series(&self) -> Series {
         CategoricalChunked::full_null(self.name(), 1).into_series()
     }
-    fn mean_as_series(&self) -> Series {
-        CategoricalChunked::full_null(self.name(), 1).into_series()
-    }
     fn median_as_series(&self) -> Series {
         CategoricalChunked::full_null(self.name(), 1).into_series()
     }

polars/polars-core/src/series/implementations/dates_time.rs

@@ -493,12 +493,6 @@ macro_rules! impl_dyn_series {
             fn min_as_series(&self) -> Series {
                 self.0.min_as_series().$into_logical()
             }
-            fn mean_as_series(&self) -> Series {
-                Int32Chunked::full_null(self.name(), 1)
-                    .cast(self.dtype())
-                    .unwrap()
-                    .into()
-            }
             fn median_as_series(&self) -> Series {
                 Int32Chunked::full_null(self.name(), 1)
                     .cast(self.dtype())

polars/polars-core/src/series/implementations/datetime.rs

@@ -532,11 +532,6 @@ impl SeriesTrait for SeriesWrap<DatetimeChunked> {
             .min_as_series()
             .into_datetime(self.0.time_unit(), self.0.time_zone().clone())
     }
-    fn mean_as_series(&self) -> Series {
-        Int32Chunked::full_null(self.name(), 1)
-            .cast(self.dtype())
-            .unwrap()
-    }
     fn median_as_series(&self) -> Series {
         Int32Chunked::full_null(self.name(), 1)
             .cast(self.dtype())

polars/polars-core/src/series/implementations/duration.rs

@@ -492,11 +492,6 @@ impl SeriesTrait for SeriesWrap<DurationChunked> {
     fn min_as_series(&self) -> Series {
         self.0.min_as_series().into_duration(self.0.time_unit())
     }
-    fn mean_as_series(&self) -> Series {
-        Int32Chunked::full_null(self.name(), 1)
-            .cast(self.dtype())
-            .unwrap()
-    }
     fn median_as_series(&self) -> Series {
         Int32Chunked::full_null(self.name(), 1)
             .cast(self.dtype())

polars/polars-core/src/series/implementations/floats.rs

@@ -487,9 +487,6 @@ macro_rules! impl_dyn_series {
             fn min_as_series(&self) -> Series {
                 ChunkAggSeries::min_as_series(&self.0)
             }
-            fn mean_as_series(&self) -> Series {
-                ChunkAggSeries::mean_as_series(&self.0)
-            }
             fn median_as_series(&self) -> Series {
                 QuantileAggSeries::median_as_series(&self.0)
             }

polars/polars-core/src/series/implementations/list.rs

@@ -228,9 +228,6 @@ impl SeriesTrait for SeriesWrap<ListChunked> {
     fn min_as_series(&self) -> Series {
         ChunkAggSeries::min_as_series(&self.0)
     }
-    fn mean_as_series(&self) -> Series {
-        ChunkAggSeries::mean_as_series(&self.0)
-    }
     fn median_as_series(&self) -> Series {
         QuantileAggSeries::median_as_series(&self.0)
     }

polars/polars-core/src/series/implementations/mod.rs

@@ -654,9 +654,6 @@ macro_rules! impl_dyn_series {
             fn min_as_series(&self) -> Series {
                 ChunkAggSeries::min_as_series(&self.0)
             }
-            fn mean_as_series(&self) -> Series {
-                ChunkAggSeries::mean_as_series(&self.0)
-            }
             fn median_as_series(&self) -> Series {
                 QuantileAggSeries::median_as_series(&self.0)
             }

polars/polars-core/src/series/implementations/object.rs

@@ -246,9 +246,6 @@ where
     fn min_as_series(&self) -> Series {
         ObjectChunked::<T>::full_null(self.name(), 1).into_series()
     }
-    fn mean_as_series(&self) -> Series {
-        ObjectChunked::<T>::full_null(self.name(), 1).into_series()
-    }
     fn median_as_series(&self) -> Series {
         ObjectChunked::<T>::full_null(self.name(), 1).into_series()
     }

polars/polars-core/src/series/implementations/utf8.rs

@@ -320,9 +320,6 @@ impl SeriesTrait for SeriesWrap<Utf8Chunked> {
     fn min_as_series(&self) -> Series {
         ChunkAggSeries::min_as_series(&self.0)
     }
-    fn mean_as_series(&self) -> Series {
-        ChunkAggSeries::mean_as_series(&self.0)
-    }
     fn median_as_series(&self) -> Series {
         QuantileAggSeries::median_as_series(&self.0)
     }

polars/polars-core/src/series/mod.rs

@@ -926,6 +926,16 @@ impl Series {
         };
         self.slice(-(len as i64), len)
     }
+
+    pub fn mean_as_series(&self) -> Series {
+        let val = [self.mean()];
+        let s = Series::new(self.name(), val);
+        if !self.is_numeric() {
+            s.cast(self.dtype()).unwrap()
+        } else {
+            s
+        }
+    }
 }
 
 impl Deref for Series {

polars/polars-core/src/series/series_trait.rs

@@ -777,10 +777,6 @@ pub trait SeriesTrait:
     fn min_as_series(&self) -> Series {
         invalid_operation_panic!(self)
     }
-    /// Get the mean of the Series as a new Series of length 1.
-    fn mean_as_series(&self) -> Series {
-        invalid_operation_panic!(self)
-    }
     /// Get the median of the Series as a new Series of length 1.
     fn median_as_series(&self) -> Series {
         invalid_operation_panic!(self)

polars/polars-lazy/src/dsl/mod.rs

@@ -2108,7 +2108,7 @@ impl Rem for Expr {
 ///
 /// It is the responsibility of the caller that the schema is correct by giving
 /// the correct output_type. If None given the output type of the input expr is used.
-pub fn map_mul<F, E>(function: F, expr: E, output_type: GetOutput) -> Expr
+pub fn map_multiple<F, E>(function: F, expr: E, output_type: GetOutput) -> Expr
 where
     F: Fn(&mut [Series]) -> Result<Series> + 'static + Send + Sync,
     E: AsRef<[Expr]>,
@@ -2135,7 +2135,7 @@ where
 ///  * `map_mul` should be used for operations that are independent of groups, e.g. `multiply * 2`, or `raise to the power`
 ///  * `apply_mul` should be used for operations that work on a group of data. e.g. `sum`, `count`, etc.
 ///  * `map_list_mul` should be used when the function expects a list aggregated series.
-pub fn map_list_mul<F, E>(function: F, expr: E, output_type: GetOutput) -> Expr
+pub fn map_list_multiple<F, E>(function: F, expr: E, output_type: GetOutput) -> Expr
 where
     F: Fn(&mut [Series]) -> Result<Series> + 'static + Send + Sync,
     E: AsRef<[Expr]>,
@@ -2164,7 +2164,7 @@ where
 ///
 /// * `[map_mul]` should be used for operations that are independent of groups, e.g. `multiply * 2`, or `raise to the power`
 /// * `[apply_mul]` should be used for operations that work on a group of data. e.g. `sum`, `count`, etc.
-pub fn apply_mul<F, E>(function: F, expr: E, output_type: GetOutput) -> Expr
+pub fn apply_multiple<F, E>(function: F, expr: E, output_type: GetOutput) -> Expr
 where
     F: Fn(&mut [Series]) -> Result<Series> + 'static + Send + Sync,
     E: AsRef<[Expr]>,

polars/polars-lazy/src/tests/logical.rs

@@ -1,5 +1,4 @@
 use super::*;
-use polars_core::prelude::TimeUnit::Milliseconds;
 use polars_core::utils::arrow::temporal_conversions::MILLISECONDS_IN_DAY;
 
 #[test]

polars/polars-lazy/src/tests/queries.rs

@@ -1850,7 +1850,7 @@ fn test_apply_multiple_columns() -> Result<()> {
     let out = df
         .clone()
         .lazy()
-        .select([map_mul(
+        .select([map_multiple(
             multiply,
             [col("A"), col("B")],
             GetOutput::from_type(DataType::Float64),
@@ -1866,7 +1866,7 @@ fn test_apply_multiple_columns() -> Result<()> {
     let out = df
         .lazy()
         .groupby_stable([col("cars")])
-        .agg([apply_mul(
+        .agg([apply_multiple(
             multiply,
             [col("A"), col("B")],
             GetOutput::from_type(DataType::Float64),

py-polars/src/lazy/apply.rs

@@ -233,8 +233,8 @@ pub fn map_mul(
         None => fld.clone(),
     });
     if apply_groups {
-        polars::lazy::dsl::apply_mul(function, exprs, output_map).into()
+        polars::lazy::dsl::apply_multiple(function, exprs, output_map).into()
     } else {
-        polars::lazy::dsl::map_mul(function, exprs, output_map).into()
+        polars::lazy::dsl::map_multiple(function, exprs, output_map).into()
     }
 }