Skip to main content

Typer, build great CLIs. Easy to code. Based on Python type hints.

Project description

Typer

Typer, build great CLIs. Easy to code. Based on Python type hints.

Test Publish Coverage Package version


Documentation: https://typer.tiangolo.com

Source Code: https://github.com/tiangolo/typer


Typer is a library for building CLI applications that users will love using and developers will love creating. Based on Python type hints.

It's also a command line tool to run scripts, automatically converting them to CLI applications.

The key features are:

  • Intuitive to write: Great editor support. Completion everywhere. Less time debugging. Designed to be easy to use and learn. Less time reading docs.
  • Easy to use: It's easy to use for the final users. Automatic help, and automatic completion for all shells.
  • Short: Minimize code duplication. Multiple features from each parameter declaration. Fewer bugs.
  • Start simple: The simplest example adds only 2 lines of code to your app: 1 import, 1 function call.
  • Grow large: Grow in complexity as much as you want, create arbitrarily complex trees of commands and groups of subcommands, with options and arguments.
  • Run scripts: Typer includes a typer command/program that you can use to run scripts, automatically converting them to CLIs, even if they don't use Typer internally.

FastAPI of CLIs

Typer is FastAPI's little sibling, it's the FastAPI of CLIs.

Installation

$ pip install typer
---> 100%
Successfully installed typer rich shellingham

Example

The absolute minimum

  • Create a file main.py with:
def main(name: str):
    print(f"Hello {name}")

This script doesn't even use Typer internally. But you can use the typer command to run it as a CLI application.

Run it

Run your application with the typer command:

// Run your application
$ typer main.py run

// You get a nice error, you are missing NAME
Usage: typer [PATH_OR_MODULE] run [OPTIONS] NAME
Try 'typer [PATH_OR_MODULE] run --help' for help.
╭─ Error ───────────────────────────────────────────╮
│ Missing argument 'NAME'.                          │
╰───────────────────────────────────────────────────╯


// You get a --help for free
$ typer main.py run --help

Usage: typer [PATH_OR_MODULE] run [OPTIONS] NAME

Run the provided Typer app.

╭─ Arguments ───────────────────────────────────────╮
│ *    name      TEXT  [default: None] [required]   |
╰───────────────────────────────────────────────────╯
╭─ Options ─────────────────────────────────────────╮
│ --help          Show this message and exit.       │
╰───────────────────────────────────────────────────╯

// Now pass the NAME argument
$ typer main.py run Camila

Hello Camila

// It works! 🎉

This is the simplest use case, not even using Typer internally, but it can already be quite useful for simple scripts.

Note: auto-completion works when you create a Python package and run it with --install-completion or when you use the typer command.

Use Typer in your code

Now let's start using Typer in your own code, update main.py with:

import typer


def main(name: str):
    print(f"Hello {name}")


if __name__ == "__main__":
    typer.run(main)

Now you could run it with Python directly:

// Run your application
$ python main.py

// You get a nice error, you are missing NAME
Usage: main.py [OPTIONS] NAME
Try 'main.py --help' for help.
╭─ Error ───────────────────────────────────────────╮
│ Missing argument 'NAME'.                          │
╰───────────────────────────────────────────────────╯


// You get a --help for free
$ python main.py --help

Usage: main.py [OPTIONS] NAME

╭─ Arguments ───────────────────────────────────────╮
│ *    name      TEXT  [default: None] [required]   |
╰───────────────────────────────────────────────────╯
╭─ Options ─────────────────────────────────────────╮
│ --help          Show this message and exit.       │
╰───────────────────────────────────────────────────╯

// Now pass the NAME argument
$ python main.py Camila

Hello Camila

// It works! 🎉

Note: you can also call this same script with the typer command, but you don't need to.

Example upgrade

This was the simplest example possible.

Now let's see one a bit more complex.

An example with two subcommands

Modify the file main.py.

Create a typer.Typer() app, and create two subcommands with their parameters.

import typer

app = typer.Typer()


@app.command()
def hello(name: str):
    print(f"Hello {name}")


@app.command()
def goodbye(name: str, formal: bool = False):
    if formal:
        print(f"Goodbye Ms. {name}. Have a good day.")
    else:
        print(f"Bye {name}!")


if __name__ == "__main__":
    app()

And that will:

  • Explicitly create a typer.Typer app.
    • The previous typer.run actually creates one implicitly for you.
  • Add two subcommands with @app.command().
  • Execute the app() itself, as if it was a function (instead of typer.run).

Run the upgraded example

Check the new help:

$ python main.py --help

 Usage: main.py [OPTIONS] COMMAND [ARGS]...

╭─ Options ─────────────────────────────────────────╮
│ --install-completion          Install completion  │
│                               for the current     │
│                               shell.              │
│ --show-completion             Show completion for │
│                               the current shell,  │
│                               to copy it or       │
│                               customize the       │
│                               installation.       │
│ --help                        Show this message   │
│                               and exit.           │
╰───────────────────────────────────────────────────╯
╭─ Commands ────────────────────────────────────────╮
│ goodbye                                           │
│ hello                                             │
╰───────────────────────────────────────────────────╯

// When you create a package you get ✨ auto-completion ✨ for free, installed with --install-completion

// You have 2 subcommands (the 2 functions): goodbye and hello

Now check the help for the hello command:

$ python main.py hello --help

 Usage: main.py hello [OPTIONS] NAME

╭─ Arguments ───────────────────────────────────────╮
│ *    name      TEXT  [default: None] [required]   │
╰───────────────────────────────────────────────────╯
╭─ Options ─────────────────────────────────────────╮
│ --help          Show this message and exit.       │
╰───────────────────────────────────────────────────╯

And now check the help for the goodbye command:

$ python main.py goodbye --help

 Usage: main.py goodbye [OPTIONS] NAME

╭─ Arguments ───────────────────────────────────────╮
│ *    name      TEXT  [default: None] [required]   │
╰───────────────────────────────────────────────────╯
╭─ Options ─────────────────────────────────────────╮
│ --formal    --no-formal      [default: no-formal] │
│ --help                       Show this message    │
│                              and exit.            │
╰───────────────────────────────────────────────────╯

// Automatic --formal and --no-formal for the bool option 🎉

Now you can try out the new command line application:

// Use it with the hello command

$ python main.py hello Camila

Hello Camila

// And with the goodbye command

$ python main.py goodbye Camila

Bye Camila!

// And with --formal

$ python main.py goodbye --formal Camila

Goodbye Ms. Camila. Have a good day.

Recap

In summary, you declare once the types of parameters (CLI arguments and CLI options) as function parameters.

You do that with standard modern Python types.

You don't have to learn a new syntax, the methods or classes of a specific library, etc.

Just standard Python.

For example, for an int:

total: int

or for a bool flag:

force: bool

And similarly for files, paths, enums (choices), etc. And there are tools to create groups of subcommands, add metadata, extra validation, etc.

You get: great editor support, including completion and type checks everywhere.

Your users get: automatic --help, auto-completion in their terminal (Bash, Zsh, Fish, PowerShell) when they install your package or when using the typer command.

For a more complete example including more features, see the Tutorial - User Guide.

Dependencies

Typer stands on the shoulders of a giant. Its only internal required dependency is Click.

By default it also comes with extra standard dependencies:

  • rich: to show nicely formatted errors automatically.
  • shellingham: to automatically detect the current shell when installing completion.
    • With shellingham you can just use --install-completion.
    • Without shellingham, you have to pass the name of the shell to install completion for, e.g. --install-completion bash.

typer-slim

If you don't want the extra standard optional dependencies, install typer-slim instead.

When you install with:

pip install typer

...it includes the same code and dependencies as:

pip install "typer-slim[standard]"

The standard extra dependencies are rich and shellingham.

Note: The typer command is only included in the typer package.

License

This project is licensed under the terms of the MIT license.

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

typer-0.12.3.tar.gz (94.3 kB view details)

Uploaded Source

Built Distribution

typer-0.12.3-py3-none-any.whl (47.2 kB view details)

Uploaded Python 3

File details

Details for the file typer-0.12.3.tar.gz.

File metadata

  • Download URL: typer-0.12.3.tar.gz
  • Upload date:
  • Size: 94.3 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/4.0.2 CPython/3.11.9

File hashes

Hashes for typer-0.12.3.tar.gz
Algorithm Hash digest
SHA256 49e73131481d804288ef62598d97a1ceef3058905aa536a1134f90891ba35482
MD5 1e88963a4bba50bc07885a02ba620943
BLAKE2b-256 ac0ad55af35db5f50f486e3eda0ada747eed773859e2699d3ce570b682a9b70a

See more details on using hashes here.

File details

Details for the file typer-0.12.3-py3-none-any.whl.

File metadata

  • Download URL: typer-0.12.3-py3-none-any.whl
  • Upload date:
  • Size: 47.2 kB
  • Tags: Python 3
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/4.0.2 CPython/3.11.9

File hashes

Hashes for typer-0.12.3-py3-none-any.whl
Algorithm Hash digest
SHA256 070d7ca53f785acbccba8e7d28b08dcd88f79f1fbda035ade0aecec71ca5c914
MD5 49b1dd6e6661a4271390c766361ecb4a
BLAKE2b-256 20b511cf2e34fbb11b937e006286ab5b8cfd334fde1c8fa4dd7f491226931180

See more details on using hashes here.

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page