use setuptools_scm for versioning (#14)

* use setuptools_scm

* actually use setuptools_scm

Author: keewis

pintxarray/__init__.py

@@ -1 +1,13 @@
+try:
+    from importlib.metadata import version
+except ImportError:
+    from importlib_metadata import version
+
 from .accessors import PintDataArrayAccessor, PintDatasetAccessor  # noqa
+
+try:
+    __version__ = version("pint-xarray")
+except Exception:
+    # Local copy or not installed with setuptools.
+    # Disable minimum version checks on downstream libraries.
+    __version__ = "999"

pyproject.toml

@@ -1,3 +1,5 @@
 [build-system]
-requires = ["setuptools >= 41", "wheel"]
-build-backend = "setuptools.build_meta"
+requires = ["setuptools >= 42", "wheel", "setuptools_scm[toml] >= 3.4"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools_scm]

setup.cfg

@@ -1,6 +1,5 @@
 [metadata]
 name = pint-xarray
-version = 0.0.1
 author = Tom Nicholas
 author_email = [email protected]
 description = Physical units interface to xarray using Pint
@@ -9,7 +8,11 @@ url = https://github.com/TomNicholas/pint-xarray
 [options]
 packages = find:
 python_requires = >=3.6
-install_requires = numpy>=1.17.1; xarray>=0.15.1; pint>=0.12
+install_requires =
+    numpy >= 1.17.1
+    xarray >= 0.15.1
+    pint >= 0.13
+    importlib-metadata; python_version < "3.8"
 
 [flake8]
 ignore =