A new type of shell
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WMR b67b6f7fc5
Add a datepart expression for dfr to be used with dfr with-column (#9285)
# Description

Today the only way to extract date parts from a dfr series is the dfr
get-* set of commands. These create a new dataframe with just the
datepart in it, which is almost entirely useless. As far as I can tell
there's no way to append it as a series in the original dataframe. In
discussion with fdncred on Discord we decided the best route was to add
an expression for modifying columns created in dfr with-column. These
are the way you manipulate series within a data frame.

I'd like feedback on this approach - I think it's a fair way to handle
things. An example to test it would be:

```[[ record_time]; [ (date now)]]  | dfr into-df | dfr with-column [ ((dfr col record_time) | dfr datepart nanosecond | dfr as "ns" ), (dfr col record_time | dfr datepart second | dfr as "s"), (dfr col record_time | dfr datepart minute | dfr as "m"), (dfr col record_time | dfr datepart hour | dfr as "h") ]```

I'm also proposing we deprecate the dfr get-* commands.  I've not been able to figure out any meaningful way they could ever be useful, and this approach makes more sense by attaching the extracted date part to the row in the original dataframe as a new column.

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# User-Facing Changes

add in dfr datepart as an expression
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# Tests + Formatting
Need to add some better assertive tests.  I'm also not sure how to properly write the test_dataframe at the bottom, but will revisit as part of this PR.  Wanted to get feedback early.

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Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

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> **Note**
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# After Submitting
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---------

Co-authored-by: Robert Waugh <robert@waugh.io>
2023-05-30 09:41:18 -05:00
.cargo reset stack size to 10mb vs 2gb (#7103) 2022-11-11 15:22:26 -06:00
.githooks Add git hooks for formatting and running clippy (#8820) 2023-04-13 07:34:23 -05:00
.github CI: disable nu-coverage (#9251) 2023-05-21 11:44:21 +02:00
assets REFACTOR: clean the root of the repo (#9231) 2023-05-20 07:57:51 -05:00
benches improve operation mismatch errors (#8800) 2023-04-08 09:32:44 +12:00
crates Add a datepart expression for dfr to be used with dfr with-column (#9285) 2023-05-30 09:41:18 -05:00
docker Add cross-rs config (#7559) 2022-12-22 08:52:07 -06:00
scripts add a new toolkit install command with --features support (#9288) 2023-05-26 11:22:34 +02:00
src Merge stack before printing (#9304) 2023-05-29 19:03:00 -05:00
tests Allow recursive module dirs; Require mod.nu in dirs (#9185) 2023-05-13 01:20:33 +03:00
wix fix some typos (#7773) 2023-01-16 12:43:46 +01:00
.gitignore Update .gitignore (#8717) 2023-04-02 21:28:42 +02:00
.typos.toml Add Github Actions workflow to check for typos (#7892) 2023-01-29 10:22:56 +13:00
Cargo.lock update most dependencies except where deeper code changes are needed (#9296) 2023-05-26 10:32:48 -05:00
Cargo.toml update most dependencies except where deeper code changes are needed (#9296) 2023-05-26 10:32:48 -05:00
CODE_OF_CONDUCT.md First pass at updating all documentation formatting and cleaning up output of examples (#2031) 2020-06-24 06:21:47 +12:00
codecov.yml Disable Windows coverage tracking for now (#8190) 2023-02-24 13:05:05 +01:00
CONTRIBUTING.md document how to run dataframe tests as well (#9188) 2023-05-13 09:18:37 -07:00
Cross.toml Add cross-rs config (#7559) 2022-12-22 08:52:07 -06:00
LICENSE Update LICENSE 2023-04-03 08:23:19 +12:00
README.md REFACTOR: clean the root of the repo (#9231) 2023-05-20 07:57:51 -05:00
rust-toolchain.toml Update rust-toolchain.toml to 1.67.1 (#9012) 2023-04-27 09:31:29 -05:00
toolkit.nu add a new toolkit install command with --features support (#9288) 2023-05-26 11:22:34 +02:00

Nushell

Crates.io Build Status Discord The Changelog #363 @nu_shell GitHub commit activity GitHub contributors codecov

A new type of shell.

Example of nushell

Table of Contents

Status

This project has reached a minimum-viable-product level of quality. Many people use it as their daily driver, but it may be unstable for some commands. Nu's design is subject to change as it matures.

Learning About Nu

The Nushell book is the primary source of Nushell documentation. You can find a full list of Nu commands in the book, and we have many examples of using Nu in our cookbook.

We're also active on Discord and Twitter; come and chat with us!

Installation

To quickly install Nu:

# Linux and macOS
brew install nushell
# Windows
winget install nushell

To use Nu in GitHub Action, check setup-nu for more detail.

Detailed installation instructions can be found in the installation chapter of the book. Nu is available via many package managers:

Packaging status

Configuration

The default configurations can be found at sample_config which are the configuration files one gets when they startup Nushell for the first time.

It sets all of the default configuration to run Nushell. From here one can then customize this file for their specific needs.

To see where config.nu is located on your system simply type this command.

$nu.config-path

Please see our book for all of the Nushell documentation.

Philosophy

Nu draws inspiration from projects like PowerShell, functional programming languages, and modern CLI tools. Rather than thinking of files and data as raw streams of text, Nu looks at each input as something with structure. For example, when you list the contents of a directory what you get back is a table of rows, where each row represents an item in that directory. These values can be piped through a series of steps, in a series of commands called a 'pipeline'.

Pipelines

In Unix, it's common to pipe between commands to split up a sophisticated command over multiple steps. Nu takes this a step further and builds heavily on the idea of pipelines. As in the Unix philosophy, Nu allows commands to output to stdout and read from stdin. Additionally, commands can output structured data (you can think of this as a third kind of stream). Commands that work in the pipeline fit into one of three categories:

  • Commands that produce a stream (e.g., ls)
  • Commands that filter a stream (e.g., where type == "dir")
  • Commands that consume the output of the pipeline (e.g., table)

Commands are separated by the pipe symbol (|) to denote a pipeline flowing left to right.

> ls | where type == "dir" | table
╭────┬──────────┬──────┬─────────┬───────────────╮
│ #  │   name   │ type │  size   │   modified    │
├────┼──────────┼──────┼─────────┼───────────────┤
│  0 │ .cargo   │ dir  │     0 B │ 9 minutes ago │
│  1 │ assets   │ dir  │     0 B │ 2 weeks ago   │
│  2 │ crates   │ dir  │ 4.0 KiB │ 2 weeks ago   │
│  3 │ docker   │ dir  │     0 B │ 2 weeks ago   │
│  4 │ docs     │ dir  │     0 B │ 2 weeks ago   │
│  5 │ images   │ dir  │     0 B │ 2 weeks ago   │
│  6 │ pkg_mgrs │ dir  │     0 B │ 2 weeks ago   │
│  7 │ samples  │ dir  │     0 B │ 2 weeks ago   │
│  8 │ src      │ dir  │ 4.0 KiB │ 2 weeks ago   │
│  9 │ target   │ dir  │     0 B │ a day ago     │
│ 10 │ tests    │ dir  │ 4.0 KiB │ 2 weeks ago   │
│ 11 │ wix      │ dir  │     0 B │ 2 weeks ago   │
╰────┴──────────┴──────┴─────────┴───────────────╯

Because most of the time you'll want to see the output of a pipeline, table is assumed. We could have also written the above:

> ls | where type == "dir"

Being able to use the same commands and compose them differently is an important philosophy in Nu. For example, we could use the built-in ps command to get a list of the running processes, using the same where as above.

> ps | where cpu > 0
╭───┬───────┬───────────┬───────┬───────────┬───────────╮
│ # │  pid  │   name    │  cpu  │    mem    │  virtual  │
├───┼───────┼───────────┼───────┼───────────┼───────────┤
│ 02240 │ Slack.exe │ 16.40 │ 178.3 MiB │ 232.6 MiB │
│ 116948 │ Slack.exe │ 16.32 │ 205.0 MiB │ 197.9 MiB │
│ 217700 │ nu.exe    │  3.77 │  26.1 MiB │   8.8 MiB │
╰───┴───────┴───────────┴───────┴───────────┴───────────╯

Opening files

Nu can load file and URL contents as raw text or structured data (if it recognizes the format). For example, you can load a .toml file as structured data and explore it:

> open Cargo.toml
╭──────────────────┬────────────────────╮
│ bin              │ [table 1 row]      │
│ dependencies     │ {record 25 fields} │
│ dev-dependencies │ {record 8 fields}  │
│ features         │ {record 10 fields} │
│ package          │ {record 13 fields} │
│ patch            │ {record 1 field}   │
│ profile          │ {record 3 fields}  │
│ target           │ {record 3 fields}  │
│ workspace        │ {record 1 field}   │
╰──────────────────┴────────────────────╯

We can pipe this into a command that gets the contents of one of the columns:

> open Cargo.toml | get package
╭───────────────┬────────────────────────────────────╮
│ authors       │ [list 1 item]                      │
│ default-run   │ nu                                 │
│ description   │ A new type of shell                │
│ documentation │ https://www.nushell.sh/book/       │
│ edition       │ 2018                               │
│ exclude       │ [list 1 item]                      │
│ homepage      │ https://www.nushell.sh             │
│ license       │ MIT                                │
│ metadata      │ {record 1 field}                   │
│ name          │ nu                                 │
│ repository    │ https://github.com/nushell/nushell │
│ rust-version  │ 1.60                               │
│ version       │ 0.72.0                             │
╰───────────────┴────────────────────────────────────╯

And if needed we can drill down further:

> open Cargo.toml | get package.version
0.72.0

Plugins

Nu supports plugins that offer additional functionality to the shell and follow the same structured data model that built-in commands use. There are a few examples in the crates/nu_plugins_* directories.

Plugins are binaries that are available in your path and follow a nu_plugin_* naming convention. These binaries interact with nu via a simple JSON-RPC protocol where the command identifies itself and passes along its configuration, making it available for use. If the plugin is a filter, data streams to it one element at a time, and it can stream data back in return via stdin/stdout. If the plugin is a sink, it is given the full vector of final data and is given free reign over stdin/stdout to use as it pleases.

The awesome-nu repo lists a variety of nu-plugins while the showcase repo shows off informative blog posts that have been written about Nushell along with videos that highlight technical topics that have been presented.

Goals

Nu adheres closely to a set of goals that make up its design philosophy. As features are added, they are checked against these goals.

  • First and foremost, Nu is cross-platform. Commands and techniques should work across platforms and Nu has first-class support for Windows, macOS, and Linux.

  • Nu ensures compatibility with existing platform-specific executables.

  • Nu's workflow and tools should have the usability expected of modern software in 2022 (and beyond).

  • Nu views data as either structured or unstructured. It is a structured shell like PowerShell.

  • Finally, Nu views data functionally. Rather than using mutation, pipelines act as a means to load, change, and save data without mutable state.

Progress

Nu is under heavy development and will naturally change as it matures. The chart below isn't meant to be exhaustive, but it helps give an idea for some of the areas of development and their relative maturity:

Features Not started Prototype MVP Preview Mature Notes
Aliases X Aliases allow for shortening large commands, while passing flags
Notebook X Initial jupyter support, but it loses state and lacks features
File ops X cp, mv, rm, mkdir have some support, but lacking others
Environment X Temporary environment and scoped environment variables
Shells X Basic value and file shells, but no opt-in/opt-out for commands
Protocol X Streaming protocol is serviceable
Plugins X Plugins work on one row at a time, lack batching and expression eval
Errors X Error reporting works, but could use usability polish
Documentation X Book updated to latest release, including usage examples
Paging X Textview has paging, but we'd like paging for tables
Functions X Functions and aliases are supported
Variables X Nu supports variables and environment variables
Completions X Completions for filepaths
Type-checking x Commands check basic types, and input/output types

Officially Supported By

Please submit an issue or PR to be added to this list.

Contributing

See Contributing for details. Thanks to all the people who already contributed!

License

The project is made available under the MIT license. See the LICENSE file for more information.