dynamically generate version from tags

Use setuptools-scm to get a version from the tag
when released instead of looking for the contents
of a file. Generate a version.py file to replace
the static value in __init__.py.

.gitignore

@@ -8,3 +8,4 @@ sacrebleu.egg-info
 *~
 .DS_Store
 .idea/
+sacrebleu/version.py

pyproject.toml

@@ -1,10 +1,10 @@
 [build-system]
-requires = ["setuptools>=64"]
+requires = ["setuptools>=64", "setuptools_scm>=8"]
 build-backend = "setuptools.build_meta"
 
 [project]
 name = "sacrebleu"
-version = "2.4.1"
+dynamic = ["version"]
 authors = [{ name = "Matt Post", email = "post@cs.jhu.edu" }]
 maintainers = [{ name = "Matt Post", email = "post@cs.jhu.edu" }]
 description = "Hassle-free computation of shareable, comparable, and reproducible BLEU, chrF, and TER scores"
@@ -72,3 +72,6 @@ Repository = "https://github.com/mjpost/sacrebleu"
 
 [tool.setuptools.package-data]
 sacrebleu = ["py.typed"]
+
+[tool.setuptools_scm]
+version_file = "sacrebleu/version.py"

sacrebleu/__init__.py

@@ -14,7 +14,6 @@
 # express or implied. See the License for the specific language governing
 # permissions and limitations under the License.
 
-__version__ = '2.4.1'
 __description__ = 'Hassle-free computation of shareable, comparable, and reproducible BLEU, chrF, and TER scores'
 
 
@@ -24,6 +23,7 @@
 from .metrics.helpers import extract_word_ngrams, extract_char_ngrams
 from .dataset import DATASETS
 from .metrics import BLEU, CHRF, TER
+from .version import __version__
 
 # Backward compatibility functions for old style API access (<= 1.4.10)
 from .compat import corpus_bleu, raw_corpus_bleu, sentence_bleu
@@ -40,4 +40,5 @@
     'corpus_bleu', 'raw_corpus_bleu', 'sentence_bleu',
     'corpus_chrf', 'sentence_chrf',
     'corpus_ter', 'sentence_ter'
+    '__version__',
 ]