Dataframe new commands (#3425)

* Folder for dataframe commands

* New commands for dataframe

crates/nu-command/src/commands.rs

@@ -187,7 +187,7 @@ pub(crate) mod touch;
 pub(crate) use all::Command as All;
 pub(crate) use any::Command as Any;
 #[cfg(feature = "dataframe")]
-pub(crate) use dataframe::Dataframe;
+pub(crate) use dataframe::{Dataframe, DataframeList, DataframeLoad};
 pub(crate) use enter::Enter;
 pub(crate) use every::Every;
 pub(crate) use exec::Exec;

crates/nu-command/src/commands/dataframe/command.rs

@@ -0,0 +1,38 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{dataframe::NuDataFrame, Signature, UntaggedValue};
+
+pub struct Command;
+
+impl WholeStreamCommand for Command {
+    fn name(&self) -> &str {
+        "dataframe"
+    }
+
+    fn usage(&self) -> &str {
+        "Creates a dataframe from pipelined Table or List "
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe")
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        let tag = args.call_info.name_tag.clone();
+        let args = args.evaluate_once()?;
+
+        let df = NuDataFrame::try_from_iter(args.input, &tag)?;
+        let init = InputStream::one(UntaggedValue::Dataframe(df).into_value(&tag));
+
+        Ok(init.to_output_stream())
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Takes an input stream and converts it to a dataframe",
+            example: "echo [[a b];[1 2] [3 4]] | dataframe",
+            result: None,
+        }]
+    }
+}

crates/nu-command/src/commands/dataframe/list.rs

@@ -0,0 +1,53 @@
+use crate::prelude::*;
+use nu_engine::WholeStreamCommand;
+use nu_errors::ShellError;
+use nu_protocol::{Signature, TaggedDictBuilder, UntaggedValue, Value};
+
+pub struct Dataframe;
+
+impl WholeStreamCommand for Dataframe {
+    fn name(&self) -> &str {
+        "dataframe list"
+    }
+
+    fn usage(&self) -> &str {
+        "Lists stored dataframes"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("dataframe list")
+    }
+
+    fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
+        let args = args.evaluate_once()?;
+
+        let mut dataframes: Vec<Value> = Vec::new();
+        for (name, value) in args.context.scope.get_vars() {
+            if let UntaggedValue::Dataframe(df) = value.value {
+                let mut data = TaggedDictBuilder::new(value.tag);
+
+                let polars_df = df.dataframe.unwrap();
+
+                let rows = polars_df.height();
+                let cols = polars_df.width();
+
+                data.insert_value("name", name);
+                data.insert_value("file", df.name);
+                data.insert_value("rows", format!("{}", rows));
+                data.insert_value("columns", format!("{}", cols));
+
+                dataframes.push(data.into_value());
+            }
+        }
+
+        Ok(OutputStream::from_stream(dataframes.into_iter()))
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Lists loaded dataframes in current scope",
+            example: "dataframe list",
+            result: None,
+        }]
+    }
+}

crates/nu-command/src/commands/dataframe/load.rs

@@ -3,82 +3,47 @@ use std::path::PathBuf;
 use crate::prelude::*;
 use nu_engine::WholeStreamCommand;
 use nu_errors::ShellError;
-use nu_protocol::{dataframe::NuDataFrame, hir::NamedValue, Signature, SyntaxShape, UntaggedValue};
+use nu_protocol::{dataframe::NuDataFrame, Signature, SyntaxShape, UntaggedValue};
 
 use nu_source::Tagged;
 use polars::prelude::{CsvReader, SerReader};
 
 pub struct Dataframe;
 
-#[derive(Deserialize)]
-pub struct OpenArgs {
-    file: Tagged<PathBuf>,
-}
-
 impl WholeStreamCommand for Dataframe {
     fn name(&self) -> &str {
-        "dataframe"
+        "dataframe load"
     }
 
     fn usage(&self) -> &str {
-        "Creates a dataframe from a csv file"
+        "Loads dataframe form csv or parquet file"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("dataframe").named(
+        Signature::build("dataframe load").required(
             "file",
             SyntaxShape::FilePath,
             "the file path to load values from",
-            Some('f'),
         )
     }
 
     fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
-        load_dataframe(args)
+        create_from_file(args)
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![
-            Example {
-                description: "Takes a file name and creates a dataframe",
-                example: "dataframe -f test.csv",
-                result: None,
-            },
-            Example {
-                description: "Takes an input stream and converts it to a dataframe",
-                example: "echo [[a b];[1 2] [3 4]] | dataframe",
-                result: None,
-            },
-        ]
+        vec![Example {
+            description: "Takes a file name and creates a dataframe",
+            example: "dataframe load test.csv",
+            result: None,
+        }]
     }
 }
 
-// Creates a dataframe from either a file or a table.
-// If both options are found, then an error is returned to the user.
-// The InputStream can have a table and a dictionary as input variable.
-fn load_dataframe(args: CommandArgs) -> Result<OutputStream, ShellError> {
-    // The file has priority over stream input
-    if let Some(NamedValue::Value(_, _)) = args
-        .call_info()
-        .args
-        .named
-        .as_ref()
-        .map(|named| named.named.get("file"))
-        .flatten()
-    {
-        return create_from_file(args);
-    }
-
-    create_from_input(args)
-}
-
 fn create_from_file(args: CommandArgs) -> Result<OutputStream, ShellError> {
-    // Command Tag. This marks where the command is located and the name
-    // of the command used
     let tag = args.call_info.name_tag.clone();
-
-    // Parsing the arguments that the function uses
-    let (OpenArgs { file }, _) = args.process()?;
+    let args = args.evaluate_once()?;
+    let file: Tagged<PathBuf> = args.req(0)?;
 
     // Needs more detail and arguments while loading the dataframe
     // Options:
@@ -128,12 +93,3 @@ fn create_from_file(args: CommandArgs) -> Result<OutputStream, ShellError> {
 
     Ok(init.to_output_stream())
 }
-
-fn create_from_input(args: CommandArgs) -> Result<OutputStream, ShellError> {
-    let tag = args.call_info.name_tag.clone();
-    let args = args.evaluate_once()?;
-    let df = NuDataFrame::try_from_iter(args.input, &tag)?;
-    let init = InputStream::one(UntaggedValue::Dataframe(df).into_value(&tag));
-
-    Ok(init.to_output_stream())
-}

crates/nu-command/src/commands/dataframe/mod.rs

@@ -0,0 +1,7 @@
+pub mod command;
+pub mod list;
+pub mod load;
+
+pub use command::Command as Dataframe;
+pub use list::Dataframe as DataframeList;
+pub use load::Dataframe as DataframeLoad;

crates/nu-command/src/commands/default_context.rs

@@ -253,6 +253,10 @@ pub fn create_default_context(interactive: bool) -> Result<EvaluationContext, Bo
             whole_stream_command(TermSize),
             #[cfg(feature = "dataframe")]
             whole_stream_command(Dataframe),
+            #[cfg(feature = "dataframe")]
+            whole_stream_command(DataframeLoad),
+            #[cfg(feature = "dataframe")]
+            whole_stream_command(DataframeList),
         ]);
 
         #[cfg(feature = "clipboard-cli")]