This is part of on-going work with capabilities when working with

tables and able to work with them for data processing & viewing
purposes. At the moment, certain ways to process said tables we
are able to view a histogram of a given column.

As usage matures, we may find certain core commands that could
be used ergonomically when working with tables on Nu.

README.md

@@ -256,6 +256,7 @@ Nu adheres closely to a set of goals that make up its design philosophy. As feat
 | format pattern | Format table row data as a string following the given pattern |
 | get column-or-column-path | Open column and get data from the corresponding cells |
 | group-by column | Creates a new table with the data from the table rows grouped by the column given |
+| histogram column ...column-names | Creates a new table with a histogram based on the column name passed in, optionally give the frequency column name
 | inc (column-or-column-path) | Increment a value or version. Optionally use the column of a table |
 | insert column-or-column-path value | Insert a new column to the table |
 | last amount | Show only the last number of rows |
@@ -267,6 +268,7 @@ Nu adheres closely to a set of goals that make up its design philosophy. As feat
 | reverse | Reverses the table. |
 | skip amount | Skip a number of rows |
 | skip-while condition | Skips rows while the condition matches. |
+| split-by column | Creates a new table with the data from the inner tables splitted by the column given |
 | sort-by ...columns | Sort by the given columns |
 | str (column) | Apply string function. Optionally use the column of a table |
 | sum | Sum a column of values |

src/cli.rs

@@ -301,6 +301,7 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
             whole_stream_command(FromYML),
             whole_stream_command(Pick),
             whole_stream_command(Get),
+            whole_stream_command(Histogram),
             per_item_command(Remove),
             per_item_command(Fetch),
             per_item_command(Open),
@@ -320,6 +321,7 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
             per_item_command(Mkdir),
             per_item_command(Move),
             whole_stream_command(Save),
+            whole_stream_command(SplitBy),
             whole_stream_command(Table),
             whole_stream_command(Version),
             whole_stream_command(Which),
@@ -328,12 +330,10 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
         cfg_if::cfg_if! {
             if #[cfg(data_processing_primitives)] {
                 context.add_commands(vec![
-                whole_stream_command(SplitBy),
                 whole_stream_command(ReduceBy),
                 whole_stream_command(EvaluateBy),
                 whole_stream_command(TSortBy),
                 whole_stream_command(MapMaxBy),
-                whole_stream_command(Histogram),
                 ]);
             }
         }

src/commands.rs

@@ -16,6 +16,8 @@ pub(crate) mod debug;
 pub(crate) mod echo;
 pub(crate) mod enter;
 pub(crate) mod env;
+#[allow(unused)]
+pub(crate) mod evaluate_by;
 pub(crate) mod exit;
 pub(crate) mod fetch;
 pub(crate) mod first;
@@ -33,10 +35,13 @@ pub(crate) mod from_yaml;
 pub(crate) mod get;
 pub(crate) mod group_by;
 pub(crate) mod help;
+pub(crate) mod histogram;
 pub(crate) mod history;
 pub(crate) mod last;
 pub(crate) mod lines;
 pub(crate) mod ls;
+#[allow(unused)]
+pub(crate) mod map_max_by;
 pub(crate) mod mkdir;
 pub(crate) mod mv;
 pub(crate) mod next;
@@ -49,6 +54,8 @@ pub(crate) mod post;
 pub(crate) mod prepend;
 pub(crate) mod prev;
 pub(crate) mod pwd;
+#[allow(unused)]
+pub(crate) mod reduce_by;
 pub(crate) mod reject;
 pub(crate) mod reverse;
 pub(crate) mod rm;
@@ -57,20 +64,11 @@ pub(crate) mod shells;
 pub(crate) mod size;
 pub(crate) mod skip_while;
 pub(crate) mod sort_by;
-
-cfg_if::cfg_if! {
-    if #[cfg(data_processing_primitives)] {
 pub(crate) mod split_by;
-        pub(crate) mod reduce_by;
-        pub(crate) mod evaluate_by;
-        pub(crate) mod t_sort_by;
-        pub(crate) mod map_max_by;
-        pub(crate) mod histogram;
-    }
-}
-
 pub(crate) mod split_column;
 pub(crate) mod split_row;
+#[allow(unused)]
+pub(crate) mod t_sort_by;
 pub(crate) mod table;
 pub(crate) mod tags;
 pub(crate) mod to_bson;
@@ -103,6 +101,8 @@ pub(crate) use debug::Debug;
 pub(crate) use echo::Echo;
 pub(crate) use enter::Enter;
 pub(crate) use env::Env;
+#[allow(unused)]
+pub(crate) use evaluate_by::EvaluateBy;
 pub(crate) use exit::Exit;
 pub(crate) use fetch::Fetch;
 pub(crate) use first::First;
@@ -122,10 +122,13 @@ pub(crate) use from_yaml::FromYML;
 pub(crate) use get::Get;
 pub(crate) use group_by::GroupBy;
 pub(crate) use help::Help;
+pub(crate) use histogram::Histogram;
 pub(crate) use history::History;
 pub(crate) use last::Last;
 pub(crate) use lines::Lines;
 pub(crate) use ls::LS;
+#[allow(unused)]
+pub(crate) use map_max_by::MapMaxBy;
 pub(crate) use mkdir::Mkdir;
 pub(crate) use mv::Move;
 pub(crate) use next::Next;
@@ -137,6 +140,8 @@ pub(crate) use post::Post;
 pub(crate) use prepend::Prepend;
 pub(crate) use prev::Previous;
 pub(crate) use pwd::PWD;
+#[allow(unused)]
+pub(crate) use reduce_by::ReduceBy;
 pub(crate) use reject::Reject;
 pub(crate) use reverse::Reverse;
 pub(crate) use rm::Remove;
@@ -145,20 +150,11 @@ pub(crate) use shells::Shells;
 pub(crate) use size::Size;
 pub(crate) use skip_while::SkipWhile;
 pub(crate) use sort_by::SortBy;
-
-cfg_if::cfg_if! {
-    if #[cfg(data_processing_primitives)] {
 pub(crate) use split_by::SplitBy;
-        pub(crate) use reduce_by::ReduceBy;
-        pub(crate) use evaluate_by::EvaluateBy;
-        pub(crate) use t_sort_by::TSortBy;
-        pub(crate) use map_max_by::MapMaxBy;
-        pub(crate) use histogram::Histogram;
-    }
-}
-
 pub(crate) use split_column::SplitColumn;
 pub(crate) use split_row::SplitRow;
+#[allow(unused)]
+pub(crate) use t_sort_by::TSortBy;
 pub(crate) use table::Table;
 pub(crate) use tags::Tags;
 pub(crate) use to_bson::ToBSON;

src/commands/histogram.rs

@@ -1,10 +1,10 @@
-use crate::commands::WholeStreamCommand;
+use crate::commands::evaluate_by::evaluate;
 use crate::commands::group_by::group;
+use crate::commands::map_max_by::map_max;
+use crate::commands::reduce_by::reduce;
 use crate::commands::t_sort_by::columns_sorted;
 use crate::commands::t_sort_by::t_sort;
-use crate::commands::evaluate_by::evaluate;
-use crate::commands::reduce_by::reduce;
-use crate::commands::map_max_by::map_max;
+use crate::commands::WholeStreamCommand;
 use crate::data::TaggedDictBuilder;
 use crate::errors::ShellError;
 use crate::prelude::*;
@@ -15,6 +15,7 @@ pub struct Histogram;
 #[derive(Deserialize)]
 pub struct HistogramArgs {
     column_name: Tagged<String>,
+    rest: Vec<Tagged<String>>,
 }
 
 impl WholeStreamCommand for Histogram {
@@ -23,11 +24,16 @@ impl WholeStreamCommand for Histogram {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("histogram").required(
+        Signature::build("histogram")
+            .required(
                 "column_name",
                 SyntaxShape::String,
                 "the name of the column to graph by",
             )
+            .rest(
+                SyntaxShape::Member,
+                "column name to give the histogram's frequency column",
+            )
     }
 
     fn usage(&self) -> &str {
@@ -44,7 +50,7 @@ impl WholeStreamCommand for Histogram {
 }
 
 pub fn histogram(
-    HistogramArgs { column_name }: HistogramArgs,
+    HistogramArgs { column_name, rest }: HistogramArgs,
     RunnableContext { input, name, .. }: RunnableContext,
 ) -> Result<OutputStream, ShellError> {
     let stream = async_stream! {
@@ -68,13 +74,24 @@ pub fn histogram(
 
                 let mut idx = 0;
 
+                let column_names_supplied: Vec<_> = rest.iter().map(|f| f.item.clone()).collect();
+
+                let frequency_column_name = if column_names_supplied.is_empty() {
+                    "frecuency".to_string()
+                } else {
+                    column_names_supplied[0].clone()
+                };
+
+                let column = (*column_name).clone();
+
                 if let Tagged { item: Value::Table(start), .. } = datasets.get(0).unwrap() {
                     for percentage in start.into_iter() {
+
                         let mut fact = TaggedDictBuilder::new(&name);
-                        fact.insert_tagged("committer", group_labels.get(idx).unwrap().clone());
+                        fact.insert_tagged(&column, group_labels.get(idx).unwrap().clone());
 
                         if let Tagged { item: Value::Primitive(Primitive::Int(ref num)), .. } = percentage.clone() {
-                            fact.insert("activity", std::iter::repeat("*").take(num.to_i32().unwrap() as usize).collect::<String>());
+                            fact.insert(&frequency_column_name, std::iter::repeat("*").take(num.to_i32().unwrap() as usize).collect::<String>());
                         }
 
                         idx = idx + 1;
@@ -104,8 +121,7 @@ fn percentages(
         } => {
             let datasets: Vec<_> = datasets
                 .into_iter()
-                .map(|subsets| {
-                    match subsets {
+                .map(|subsets| match subsets {
                     Tagged {
                         item: Value::Table(data),
                         ..
@@ -135,7 +151,6 @@ fn percentages(
                         Value::Table(data).tagged(&tag)
                     }
                     _ => Value::Table(vec![]).tagged(&tag),
-                    }
                 })
                 .collect();
 

src/commands/map_max_by.rs

@@ -81,8 +81,7 @@ pub fn map_max(
         } => {
             let datasets: Vec<_> = datasets
                 .into_iter()
-                .map(|subsets| {
-                    match subsets {
+                .map(|subsets| match subsets {
                     Tagged {
                         item: Value::Table(data),
                         ..
@@ -103,7 +102,6 @@ pub fn map_max(
                         Value::number(data).tagged(&tag)
                     }
                     _ => Value::number(0).tagged(&tag),
-                    }
                 })
                 .collect();
 

src/commands/t_sort_by.rs

@@ -125,7 +125,7 @@ pub fn columns_sorted(
 
             keys.into_iter().map(|k| k.tagged(&origin_tag)).collect()
         }
-        _ => vec![Value::string("default").tagged(&origin_tag)]
+        _ => vec![Value::string("default").tagged(&origin_tag)],
     }
 }
 

tests/commands_test.rs

@@ -31,6 +31,35 @@ fn group_by() {
     })
 }
 
+#[test]
+fn histogram() {
+    Playground::setup("histogram_test_1", |dirs, sandbox| {
+        sandbox.with_files(vec![FileWithContentToBeTrimmed(
+            "los_tres_caballeros.csv",
+            r#"
+                first_name,last_name,rusty_at
+                Andrés,Robalino,Ecuador
+                Jonathan,Turner,Estados Unidos
+                Yehuda,Katz,Estados Unidos
+            "#,
+        )]);
+
+        let actual = nu!(
+            cwd: dirs.test(), h::pipeline(
+            r#"
+                open los_tres_caballeros.csv
+                | histogram rusty_at countries
+                | where rusty_at == "Ecuador"
+                | get countries
+                | echo $it
+            "#
+        ));
+
+        assert_eq!(actual, "**************************************************");
+        // 50%
+    })
+}
+
 #[test]
 fn group_by_errors_if_unknown_column_name() {
     Playground::setup("group_by_test_2", |dirs, sandbox| {
@@ -56,7 +85,6 @@ fn group_by_errors_if_unknown_column_name() {
     })
 }
 
-#[cfg(data_processing_primitives)]
 #[test]
 fn split_by() {
     Playground::setup("split_by_test_1", |dirs, sandbox| {
@@ -86,7 +114,6 @@ fn split_by() {
     })
 }
 
-#[cfg(data_processing_primitives)]
 #[test]
 fn split_by_errors_if_no_table_given_as_input() {
     Playground::setup("split_by_test_2", |dirs, sandbox| {