libversion 1.1.1

# Python bindings for libversion

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[](https://travis-ci.org/repology/py-libversion)
[](https://pypi.python.org/pypi/libversion)

## Purpose

Python bindings for libversion, which provides **fast**, **powerful**
and **correct** generic version string comparison algorithm.

See [libversion](https://github.com/repology/libversion) repository for
more details on the algorithm.

## Performance

**libversion** is 10x to 100x faster than other version comparison
facilities widely used in Python world.

| Facility | comps/sec |
|-------------------------------------|----------:|
| **libversion.version_compare2** | 3492.81K |
| **libversion.version_compare** | 3219.02K |
| **libversion.Version** | 374.08K |
| tuple(map(int, (v.split('.')))) | 206.02K |
| cmp_version.cmp_version | 189.15K |
| cmp_version.VersionString | 156.42K |
| distutils.version.StrictVersion | 75.00K |
| version.Version | 71.39K |
| distutils.version.LooseVersion | 51.38K |
| pkg_resources.parse_version | 22.26K |

## Correctness

**libversion** handles certain complex version cases better than other
version comparison facilities. Here are some example cases where others
fail:

| Test case | libversion | tuple | StrictVersion | LooseVersion | parse_version | cmp_version |
|-------------------------|------------|---------------|---------------|---------------|---------------|---------------|
| 1.0 == 1.0.0 | ok | incorrect (<) | ok | incorrect (<) | ok | ok |
| 1.2_3 == 1.2-3 | ok | fail | fail | incorrect (>) | incorrect (<) | ok |
| 1.2.3 == 1.2-3 | ok | fail | fail | fail | incorrect (>) | incorrect (<) |
| 1.0alpha1 == 1.0.alpha1 | ok | fail | fail | ok | ok | incorrect (>) |
| 1.0rc1 < 1.0 | ok | fail | fail | incorrect (>) | ok | incorrect (>) |
| 1.0 < 1.0patch1 | ok | fail | fail | ok | incorrect (>) | ok |
| 1.0.2a < 1.0.2g | ok | fail | fail | ok | incorrect (>) | ok |

Note 1: **fail** means that attempt to compare versions has thrown
an exception, usually bacause a library cannot parse specific version
string.

Note 2: **version** module was not able to complete any tests as it's
a strict semantic version implementation which require 3 version
components. Also, it does not support Python 3 without modification.

## Python wrapper features

- Provides API similar to C library, `version_compare(a, b)` function
- Provides more pythonic (but slower) `Version` class with overloaded
comparison operators

## Requirements

- Python 3.6+
- pkg-config
- [libversion](https://github.com/repology/libversion) 2.7.0+

## Example code

```python
from libversion import Version, version_compare

assert(version_compare("0.9", "1.1") < 0)
assert(version_compare("1.0", "1.0.0") == 0)
assert(version_compare("1.1", "0.9") > 0)

assert(Version("0.9") < Version("1.1"))
assert(Version("1.0") == Version("1.0.0"))
assert(Version("1.1") > Version("0.9"))

assert(Version("0.999") < Version("1.0alpha1"))
assert(Version("1.0alpha1") < Version("1.0alpha2"))
assert(Version("1.0alpha2") < Version("1.0beta1"))
assert(Version("1.0beta1") < Version("1.0pre1"))
assert(Version("1.0pre1") < Version("1.0rc1"))
assert(Version("1.0rc1") < Version("1.0"))
assert(Version("1.0") < Version("1.0patch1"))
```

## License

MIT license, copyright (c) 2017-2018 Dmitry Marakasov amdmi3@amdmi3.ru.