https://github.com/mondeja/importlib-metadata-argparse-version
Python's argparse version action to define CLI version with a delayed call to importlib.metadata
https://github.com/mondeja/importlib-metadata-argparse-version
argparse cli importlib metadata python version
Last synced: 6 months ago
JSON representation
Python's argparse version action to define CLI version with a delayed call to importlib.metadata
- Host: GitHub
- URL: https://github.com/mondeja/importlib-metadata-argparse-version
- Owner: mondeja
- License: bsd-3-clause
- Created: 2022-06-06T11:13:31.000Z (over 3 years ago)
- Default Branch: master
- Last Pushed: 2024-07-01T03:02:34.000Z (over 1 year ago)
- Last Synced: 2024-10-05T06:51:06.106Z (about 1 year ago)
- Topics: argparse, cli, importlib, metadata, python, version
- Language: Python
- Homepage:
- Size: 24.4 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# `importlib-metadata-argparse-version`
[![PyPI][pypi-version-badge-link]][pypi-link]
[![Python versions][pypi-pyversions-badge-link]][pypi-link]
[![License][license-image]][license-link]
[![Tests][tests-image]][tests-link]
[![Coverage status][coverage-image]][coverage-link]
Python's [`argparse`] module action to define CLI version with a delayed
call to [`importlib.metadata.version`] only when `--version` argument
is passed.
## Rationale
When you use `importlib.metadata` for adding the version to a CLI utility,
you need to import `importlib.metadata` and call
`importlib.metadata.version("")` at initialization time.
If you only want to execute other parts of the CLI
(eg. like passing the option `--help`), `importlib.metadata` will be
imported too even when is not needed at all.
The problem is easily fixed by this module.
## Usage
```python
import argparse
from importlib_metadata_argparse_version import ImportlibMetadataVersionAction
parser = argparse.ArgumentParser()
parser.add_argument(
"-v", "--version",
action=ImportlibMetadataVersionAction,
version_from="your-package-name",
)
```
This is a rough equivalent to something like:
```python
import argparse
import importlib.metadata
parser = argparse.ArgumentParser()
parser.add_argument(
"-v", "--version",
action="version",
version=importlib_metadata.version("your-package-name"),
)
```
...but with the difference that `importlib.metadata` will only be
imported when you call `--version`, so it is more efficient.
When using `ImportlibMetadataVersionAction` the `version` kwarg
accepts `%(version)s` as a placeholder like `%(prog)s`. So you
can write something like this to display the program name before the
version:
```python
parser.add_argument(
"-v", "--version",
action=ImportlibMetadataVersionAction,
version_from="your-package-name",
version="%(prog)s %(version)s",
)
# or
parser.version = "%(prog)s %(version)s"
parser.add_argument(
"-v", "--version",
action=ImportlibMetadataVersionAction,
version_from="your-package-name",
)
```
And the `version` kwarg becomes optional, being `"%(version)s"`
the default value.
### Infer package name
The argument `version_from` can be ommitted and the package name
will be inferred from the caller package location:
```python
parser.add_argument(
"-v", "--version",
action=ImportlibMetadataVersionAction,
)
```
## For convenience
If you forget to define the kwarg `version_from` in the argument or the
inferred package name is not found, an exception will be raised at
initialization time. Python's [`argparse`] built-in `"version"` action raises
an `AttributeError` **only when you call your program with `--version`**, which
is unsafe because could lead you to forget to define the `version` passing
the error unnoticed until you test it manually.
[`argparse`]: https://docs.python.org/3/library/argparse.html
[`importlib.metadata.version`]: https://docs.python.org/3/library/importlib.metadata.html?highlight=importlib%20metadata#distribution-versions
[pypi-link]: https://pypi.org/project/importlib-metadata-argparse-version
[pypi-version-badge-link]: https://img.shields.io/pypi/v/importlib-metadata-argparse-version?logo=pypi&logoColor=white
[pypi-pyversions-badge-link]: https://img.shields.io/pypi/pyversions/importlib-metadata-argparse-version?logo=python&logoColor=white
[license-image]: https://img.shields.io/pypi/l/importlib-metadata-argparse-version?color=light-green&logo=freebsd&logoColor=white
[license-link]: https://github.com/mondeja/importlib-metadata-argparse-version/blob/master/LICENSE
[tests-image]: https://img.shields.io/github/actions/workflow/status/mondeja/importlib-metadata-argparse-version/ci.yml?logo=github&label=tests&branch=master
[tests-link]: https://github.com/mondeja/importlib-metadata-argparse-version/actions?query=workflow%3ACI
[coverage-image]: https://img.shields.io/codecov/c/github/mondeja/importlib-metadata-argparse-version?logo=codecov&logoColor=white
[coverage-link]: https://app.codecov.io/gh/mondeja/importlib-metadata-argparse-version