poethepoet 0.11.0b3

A task runner that works well with poetry.

A task runner that works well with poetry.

Features

✅ Straight forward declaration of project tasks in your pyproject.toml (kind of like npm scripts)

✅ Task are run in poetry’s virtualenv by default

✅ Shell completion of task names (and global options too for zsh)

✅ Tasks can be commands (with or without a shell) or references to python functions (like tool.poetry.scripts)

✅ Short and sweet commands with extra arguments passed to the task poe [options] task [task_args]

✅ Tasks can specify and reference environment variables as if they were evaluated by a shell

✅ Tasks are self documenting, with optional help messages (just run poe without arguments)

✅ Tasks can be defined as a sequence of other tasks

✅ Works with .env files

✅ Can also be configured to execute tasks with any virtualenv or none (not just poetry)

Installation

Into your project (so it works inside poetry shell):

poetry add --dev poethepoet

And into your default python environment (so it works outside of poetry shell)

pip install poethepoet

Enable tab completion for your shell

Poe comes with tab completion scripts for bash, zsh, and fish to save you keystrokes. How to install them will depend on your shell setup.

Zsh

# oh-my-zsh
mkdir -p ~/.oh-my-zsh/completions
poe _zsh_completion > ~/.oh-my-zsh/completions/_poe

# without oh-my-zsh
mkdir -p ~/.zfunc/
poe _zsh_completion > ~/.zfunc/_poetry

Note that you’ll need to start a new shell for the new completion script to be loaded. If it still doesn’t work try adding a call to compinit to the end of your zshrc file.

Bash

# System bash
poe _bash_completion > /etc/bash_completion.d/poe.bash-completion

# Homebrew bash
poe _bash_completion > $(brew --prefix)/etc/bash_completion.d/poe.bash-completion

How to ensure installed bash completions are enabled may vary depending on your system.

Fish

# Fish
poe _fish_completion > ~/.config/fish/completions/poe.fish

# Homebrew fish
poe _fish_completion > (brew --prefix)/share/fish/vendor_completions.d/poe.fish

Basic Usage

Define tasks in your pyproject.toml

See a real example

[tool.poe.tasks]
test       = "pytest --cov=poethepoet"                                # simple command based task
mksandwich = { script = "my_package.sandwich:build" }                 # python script based task
tunnel     = { shell = "ssh -N -L 0.0.0.0:8080:$PROD:8080 $PROD &" }  # (posix) shell script based task

Run tasks with the poe cli

poe test

Additional arguments are passed to the task so

poe test -v tests/favorite_test.py

results in the following being run inside poetry’s virtualenv

pytest --cov=poethepoet -v tests/favorite_test.py

You can also run it like so if you fancy

python -m poethepoet [options] task [task_args]

Or install it as a dev dependency with poetry and run it like

poetry add --dev poethepoet
poetry run poe [options] task [task_args]

Though it that case you might like to do alias poe='poetry run poe'.

Types of task

There are four types of task: simple commands (cmd), python scripts (script), shell scripts (shell), and composite tasks (sequence).

• Command tasks contain a single command that will be executed without a shell. This covers most basic use cases for example:

  [tool.poe.tasks]
  format = "black ."  # strings are interpreted as commands by default
  clean = """
  # Multiline commands including comments work too. Unescaped whitespace is ignored.
  rm -rf .coverage
         .mypy_cache
         .pytest_cache
         dist
         ./**/__pycache__
  """
  lint = { "cmd": "pylint poethepoet" }  # Inline tables with a cmd key work too
  greet = "echo Hello $USER"  # Environment variables work, even though there's no shell!

• Script tasks contain a reference to a python callable to import and execute, for example:

  [tool.poe.tasks]
  fetch-assets = { "script" = "my_package.assets:fetch" }
  fetch-images = { "script" = "my_package.assets:fetch(only='images')" }

  As in the second example, is it possible to hard code literal arguments to the target callable.

  If extra arguments are passed to task on the command line, then they will be available to the called python function via sys.argv.

• Shell tasks are similar to simple command tasks except that they are executed inside a new shell, and can consist of multiple separate commands, command substitution, pipes, background processes, etc.

  An example use case for this might be opening some ssh tunnels in the background with one task and closing them with another like so:

  [tool.poe.tasks]
  pfwd = { "shell" = "ssh -N -L 0.0.0.0:8080:$STAGING:8080 $STAGING & ssh -N -L 0.0.0.0:5432:$STAGINGDB:5432 $STAGINGDB &" }
  pfwdstop = { "shell" = "kill $(pgrep -f "ssh -N -L .*:(8080|5432)")" }

• Composite tasks are defined as a sequence of other tasks as an array.

  By default the contents of the array are interpreted as references to other tasks (actually a ref task type), though this behaviour can be altered by setting the global default_array_item_task_type option to the name of another task type such as _cmd_, or by setting the default_item_type option locally on the sequence task.

  An example task with references

  [tool.poe.tasks]
  
  test = "pytest --cov=src"
  build = "poetry build"
  _publish = "poetry publish"
  release = ["test", "build", "_publish"]

  Note that tasks with names prefixed with _ are not included in the documentation or directly executable, but can be useful for cases where a task is only needed for a sequence.

  An example task with inline tasks expressed via inline tables

  release = [
    { cmd = "pytest --cov=src" },
    { script = "devtasks:build" },
    { ref = "_publish" },
  ]

  An example task with inline script subtasks using default_item_type

  release.sequence = [
    "devtasks:run_tests(all=True)",
    "devtasks:build",
    "devtasks:publish",
  ]
  release.default_item_type = "script"

  A failure (non-zero result) will result in the rest of the tasks in the sequence not being executed, unless the ignore_fail option is set on the task like so:

  [tool.poe.tasks]
  attempts.sequence = ["task1", "task2", "task3"]
  attempts.ignore_fail = true

Task level configuration

Task help text

You can specifiy help text to be shown alongside the task name in the list of available tasks (such as when executing poe with no arguments), by adding a help key like so:

[tool.poe.tasks]
style = {cmd = "black . --check --diff", help = "Check code style"}

Environment variables

You can specify arbitrary environment variables to be set for a task by providing the env key like so:

[tool.poe.tasks]
serve.script = "myapp:run"
serve.env = { PORT = "9001" }

Notice this example uses deep keys which can be more convenient but aren’t as well supported by some toml implementations.

The above example can be modified to only set the PORT variable if it is not already set by replacing the last line with the following:

serve.env.PORT.default "9001"

You can also specify an env file (with bashlike syntax) to load per task like so:

# .env
STAGE=dev
PASSWORD='!@#$%^&*('

[tool.poe.tasks]
serve.script = "myapp:run"
serve.envfile = ".env"

Declaring CLI options (experimental)

By default extra CLI arguments are appended to the end of a cmd task, or exposed as sys.argv in a script task. Alternatively it is possible to define CLI options that a task should accept, which will be documented in the help for that task, and exposed to the task in a way the makes the most sense for that task type.

Arguments for cmd and shell tasks

For cmd and shell tasks the values are exposed to the task as environment variables. For example given the following configuration:

[tool.poe.tasks.passby]
shell = """
echo "hello $planet";
echo "goodbye $planet";
"""
help = "Pass by a planet!"
  [tool.poe.tasks.passby.args.planet] # the key of the arg is used as the name of the variable that the given value will be exposed as
  help = "Name of the planet to pass"
  default = "earth"
  required = false                    # by default all args are optional and default to ""
  options = ["-p", "--planet"]        # options are passed to ArgumentParser.add_argument as *args, if not given the the name value, i.e. [f"--{name}"]

the resulting task can be run like:

poe passby --planet mars

Arguments for script tasks

Arguments can be defined for script tasks in the same way, but how they are exposed to the underlying python function depends on how the script is defined.

In the following example, since not parenthesis are included for the referenced function, all provided args will be passed to the function as kwargs:

[tool.poe.tasks]
build = { script = "project.util:build", args = ["dest", "version"]

Here the build method will be passed the two argument values (if provided) from the command lines as kwargs.

Note that in this example, args are given as a list of strings. This abbreviated form is equivalent to just providing a name for each argument and keeping the default values for all other configuration (including empty string for the help message).

If there’s a need to take control of how values are passed to the function, then this is also possible as demonstrated in the following example:

[tool.poe.tasks]
build = { script = "project.util:build(dest, build_version=version)", args = ["dest", "version"]

Project-wide configuration options

Global environment variables

You can configure environment variables to be set for all poe tasks in the pyproject.toml file by specifying tool.poe.env like so

[tool.poe.env]
VAR1 = "FOO"
VAR2 = "BAR"

As for the task level option, you can indicated that a variable should only be set if not already set like so:

[tool.poe.env]
VAR1.default = "FOO"

You can also specify an env file (with bashlike syntax) to load for all tasks like so:

# .env
STAGE=dev
PASSWORD='!@#$%^&*('

[tool.poe]
envfile = ".env"

Run poe from anywhere

By default poe will detect when you’re inside a project with a pyproject.toml in the root. However if you want to run it from elsewhere that is supported too by using the --root option to specify an alternate location for the toml file. The task will run with the given location as the current working directory.

In all cases the path to project root (where the pyproject.toml resides) will be available as $POE_ROOT within the command line and process.

Change the default task type

By default tasks defined as strings are interpreted as shell commands, and script tasks require the more verbose table syntax to specify. For example:

my_cmd_task = "cmd args"
my_script_task = { "script" = "my_package.my_module:run" }

This behaviour can be reversed by setting the default_task_type option in your pyproject.toml like so:

[tool.poe]
default_task_type = "script"

[tool.poe.tasks]
my_cmd_task = { "cmd" = "cmd args" }
my_script_task = "my_package.my_module:run"

Change the executor type

You can configure poe to use a specific executor by setting tool.poe.executor.type. Valid valued include:

• auto: to automatically use the most appropriate of the following executors in order

• poetry: to run tasks in the poetry managed environment

• virtualenv: to run tasks in the indicated virtualenv (or else “./.venv” if present)

• simple: to run tasks without doing any specific environment setup

For example the following configuration will cause poe to ignore the poetry environment (if present), and instead use the virtualenv at the given location relative to the parent directory.

[tool.poe.executor]
type = "virtualenv"
location = "myvenv"

See below for more details.

Usage without poetry

Poe the Poet was originally intended for use alongside poetry. But it works just as well with any other kind of virtualenv, or standalone. This behaviour is configurable via the tool.poe.executor global option (see above).

By default poe will run tasks in the poetry managed environment, if the pyproject.toml contains a tool.poetry section. If it doesn’t then poe looks for a virtualenv to use from ./.venv or ./venv relative to the pyproject.toml file. Otherwise it falls back to running tasks without any special environment management.

Contributing

There’s plenty to do, come say hi in the issues! 👋

Also check out the CONTRIBUTING.MD 🤓

TODO

☐ support conditional execution (a bit like make targets) #12

☐ support verbose mode for documentation that shows task definitions

☐ create documentation website #11

☐ support third party task or executor types (e.g. pipenv) as plugins #13

☐ provide poe as a poetry plugin #14

☐ maybe support plumbum based tasks

Licence

MIT.