Poetry helps you declare, manage and install dependencies of Python projects, ensuring you have the right stack everywhere.
The package is highly experimental at the moment so expect things to change and break. However, if you feel adventurous feedback and pull requests are greatly appreciated.
Also, be aware that the features described here are the goal that this library is aiming for and, as of now, not all of them are implemented. The dependency management is pretty much done while the packaging and publishin are not done yet.
And finally, Poetry's code is only compatible with Python 3.6+ but it can manage Python project's with previous versions without any problem.
pip install poetrypoetry supports generating completion scripts for Bash, Fish, and Zsh.
See poet help completions for full details, but the gist is as simple as using one of the following:
# Bash
poetry completions bash > /etc/bash_completion.d/poetry.bash-completion
# Bash (macOS/Homebrew)
poetry completions bash > $(brew --prefix)/etc/bash_completion.d/poetry.bash-completion
# Fish
poetry completions fish > ~/.config/fish/completions/poetry.fish
# Zsh
poetry completions zsh > ~/.zfunc/_poetryNote: you may need to restart your shell in order for the changes to take effect.
For zsh, you must then add the following line in your ~/.zshrc before
compinit:
fpath+=~/.zfuncpoetry is a tool to handle dependencies installation, building and packaging of Python packages.
It only needs one file to do all of that: poetry.toml.
[package]
name = "pypoet"
version = "0.1.0"
description = "Poet helps you declare, manage and install dependencies of Python projects, ensuring you have the right stack everywhere."
license = "MIT"
authors = [
"Sébastien Eustace <[email protected]>"
]
readme = 'README.md'
repository = "https://github.com/sdispater/poet"
homepage = "https://github.com/sdispater/poet"
keywords = ['packaging', 'poet']
include = ['poet/**/*', 'LICENSE']
python-versions = "~2.7 || ^3.2"
[dependencies]
toml = "^0.9"
requests = "^2.13"
semantic_version = "^2.6"
pygments = "^2.2"
twine = "^1.8"
wheel = "^0.29"
pip-tools = "^1.8.2"
cleo = { git = "https://github.com/sdispater/cleo.git", branch = "master" }
[dev-dependencies]
pytest = "^3.0"
pytest-cov = "^2.4"
coverage = "<4.0"
httpretty = "^0.8.14"
[scripts]
poet = 'poet:app.run'There are some things we can notice here:
- It will try to enforce semantic versioning as the best practice in version naming.
- You can specify the readme, included and excluded files: no more
MANIFEST.in.poetrywill also use VCS ignore files (like.gitignore) to populate theexcludesection. - Keywords (up to 5) can be specified and will act as tags on the packaging site.
- The dependencies sections support caret, tilde, wildcard, inequality and multiple requirements.
- You must specify the python versions for which your package is compatible.
poetry will also detect if you are inside a virtualenv and install the packages accordingly.
So, poetry can be installed globally and used everywhere.
poetry also comes with a full fledged dependency resolution library, inspired by Molinillo.
Packaging system and dependency management in Python is rather convoluted and hard to understand for newcomers.
Even for seasoned developers it might be cumbersome at times to create all files needed in a Python project: setup.py,
requirements.txt, setup.cfg, MANIFEST.in and the newly added Pipfile.
So I wanted a tool that would limit everything to a single configuration file to do: dependency management, packaging and publishing.
It takes inspiration in tools that exist in other languages, like composer (PHP) or cargo (Rust).
And, finally, there is no reliable tool to properly resolves dependencies in Python, so I started poetry
to bring an exhaustive depency resolver to the Python community.
In short: I do not like the CLI it provides, or some of the decisions made, and I think we can do a better and more intuitive one.
Also it only solves partially one problem: dependency management while I wanted something more global and accurate to manage Python projects with just one tool.
The Pipfile is just a replacement from requirements.txt but in the end you will still need to
populate your setup.py file (or setup.cfg) with the exact same dependencies you declared in your Pipfile.
So, in the end, you will still need to manage a few configuration files to properly setup your project.
This command will help you kickstart your new Python project by creating a directory structure suitable for most projects.
poetry new my-packagewill create a folder as follows:
my-project
├── poetry.toml
├── README.rst
├── my_project
└── __init__.py
├── tests
├── __init__.py
└── test_my_package
If you want to name your project differently than the folder, you can pass
the --name option:
poetry new my-folder --my-packageThe install command reads the poetry.toml file from the current directory, resolves the dependencies,
and installs them.
poetry installIf there is a poetry.lock file in the current directory,
it will use the exact versions from there instead of resolving them.
This ensures that everyone using the library will get the same versions of the dependencies.
If there is no poetry.lock file, Poetry will create one after dependency resolution.
You can specify to the command that you do not want the development dependencies installed by passing
the --no-dev option.
poetry install --no-devYou can also specify the features you want installed
by passing the --f|--features option (See Features for more info)
poetry install --features "mysql pgsql"
poetry install -f mysql -f pgsql--no-dev: Do not install dev dependencies.-f|--features: Features to install (multiple values allowed).
In order to get the latest versions of the dependencies and to update the poetry.lock file,
you should use the update command.
poetry updateThis will resolve all dependencies of the project and write the exact versions into poetry.lock.
If you just want to update a few packages and not all, you can list them as such:
poetry update requests toml--no-progress: Removes the progress display that can mess with some terminals or scripts which don't handle backspace characters.
The add command adds new packages to the poetry.toml file from the current directory.
poetry add requests pendulumThe package command builds the source and wheels archives.
--no-universal: Do not build a universal wheel.--no-wheels: Build only the source package.-c|--clean: Make a clean package.
This command builds (if not already built) and publishes the package to the remote repository.
It will automatically register the package before uploading if this is the first time it is submitted.
-r|--repository: The repository to register the package to (default:pypi). Should match a section of your~/.pypircfile.
This command searches for packages on a remote index.
poetry search requests pendulum-N|--only-name: Search only in name.
This command locks (without installing) the dependencies specified in poetry.toml.
poetry lockA poetry.toml file is composed of multiple sections.
This section describes the specifics of the package
The name of the package. Required
The version of the package. Required
This should follow semantic versioning. However it will not be enforced and you remain free to follow another specification.
A list of Python versions for which the package is compatible. Required
A short description of the package. Required
The license of the package.
The recommended notation for the most common licenses is (alphabetical):
- Apache-2.0
- BSD-2-Clause
- BSD-3-Clause
- BSD-4-Clause
- GPL-2.0
- GPL-2.0+
- GPL-3.0
- GPL-3.0+
- LGPL-2.1
- LGPL-2.1+
- LGPL-3.0
- LGPL-3.0+
- MIT
Optional, but it is highly recommended to supply this. More identifiers are listed at the SPDX Open Source License Registry.
The authors of the package. This is a list of authors and should contain at least one author.
Authors must be in the form name <email>.
The readme file of the package. Required
The file can be either README.rst or README.md.
If it's a markdown file you have to install the pandoc utility so that it can be automatically
converted to a RestructuredText file.
You also need to have the pypandoc package installed. If you install poet via
pip you can use the markdown-readme extra to do so.
pip install pypoet[markdown-readme]An URL to the website of the project. Optional
An URL to the repository of the project. Optional
An URL to the documentation of the project. Optional
A list of keywords (max: 5) that the package is related to. Optional
A list of patterns that will be included in the final package.
You can explicitly specify to Poet that a set of globs should be ignored or included for the purposes of packaging. The globs specified in the exclude field identify a set of files that are not included when a package is built.
If a VCS is being used for a package, the exclude field will be seeded with the VCS’ ignore settings (.gitignore for git for example).
[package]
# ...
include = ["package/**/*.py", "package/**/.c"]exclude = ["package/excluded.py"]If you packages lies elsewhere (say in a src directory), you can tell poet to find them from there:
include = { from = 'src', include = '**/*' }Similarly, you can tell that the src directory represent the foo package:
include = { from = 'src', include = '**/*', as = 'foo' }Poet is configured to look for dependencies on PyPi by default. Only the name and a version string are required in this case.
[dependencies]
requests = "^2.13.0"Private repositories are not supported yet but are planned.
Caret requirements allow SemVer compatible updates to a specified version.
An update is allowed if the new version number does not modify the left-most non-zero digit in the major, minor, patch grouping.
In this case, if we ran poet update requests, poet would update us to version 2.14.0 if it was available,
but would not update us to 3.0.0.
If instead we had specified the version string as ^0.1.13, poet would update to 0.1.14 but not 0.2.0.
0.0.x is not considered compatible with any other version.
Here are some more examples of caret requirements and the versions that would be allowed with them:
^1.2.3 := >=1.2.3 <2.0.0
^1.2 := >=1.2.0 <2.0.0
^1 := >=1.0.0 <2.0.0
^0.2.3 := >=0.2.3 <0.3.0
^0.0.3 := >=0.0.3 <0.0.4
^0.0 := >=0.0.0 <0.1.0
^0 := >=0.0.0 <1.0.0
Tilde requirements specify a minimal version with some ability to update. If you specify a major, minor, and patch version or only a major and minor version, only patch-level changes are allowed. If you only specify a major version, then minor- and patch-level changes are allowed.
~1.2.3 is an example of a tilde requirement.
~1.2.3 := >=1.2.3 <1.3.0
~1.2 := >=1.2.0 <1.3.0
~1 := >=1.0.0 <2.0.0
Wildcard requirements allow for any version where the wildcard is positioned.
*, 1.* and 1.2.* are examples of wildcard requirements.
* := >=0.0.0
1.* := >=1.0.0 <2.0.0
1.2.* := >=1.2.0 <1.3.0
Inequality requirements allow manually specifying a version range or an exact version to depend on.
Here are some examples of inequality requirements:
>= 1.2.0
> 1
< 2
!= 1.2.3
Multiple version requirements can also be separated with a comma, e.g. >= 1.2, < 1.5.
To depend on a library located in a git repository,
the minimum information you need to specify is the location of the repository with the git key:
[dependencies]
requests = { git = "https://github.com/requests/requests.git" }Since we haven’t specified any other information,
Poetry assumes that we intend to use the latest commit on the master branch to build our project.
You can combine the git key with the rev, tag, or branch keys to specify something else.
Here's an example of specifying that you want to use the latest commit on a branch named next:
[dependencies]
requests = { git = "https://github.com/kennethreitz/requests.git", branch = "next" }You can also specify that a dependency should be installed only for specific Python versions:
[dependencies]
pathlib2 = { version = "^2.2", python-versions = "~2.7" }[dependencies]
pathlib2 = { version = "^2.2", python-versions = ["~2.7", "^3.2"] }This section describe the scripts or executable that will be installed when installing the package
[scripts]
poetry = 'poetry:console.run'Here, we will have the poetry script installed which will execute console.run in the poetry package.
Poetry supports features to allow expression of:
- optional dependencies, which enhance a package, but are not required; and
- clusters of optional dependencies.
[package]
name = "awesome"
[features]
mysql = ["mysqlclient"]
pgsql = ["psycopg2"]
[dependencies]
# These packages are mandatory and form the core of this package’s distribution.
mandatory = "^1.0"
# A list of all of the optional dependencies, some of which are included in the
# above `features`. They can be opted into by apps.
psycopg2 = { version = "^2.7", optional = true }
mysqlclient = { version = "^1.3", optional = true }When installing packages, you can specify features by using the -f|--features option:
poet install --features "mysql pgsql"
poet install -f mysql -f pgsqlPoetry supports arbitrary plugins wich work similarly to setuptools entry points. To match the example in the setuptools documentation, you would use the following:
[plugins] # Optional super table
[plugins."blogtool.parsers"]
".rst" = "some_module::SomeClass"