use pyproject.toml [build-system] and setuptools_scm (#188)

* use pyproject.toml [build-system] and setuptools_scm

* fix __version__ in __init__

* fall back to pkg_resources

* linting

* fix docs

* CHANGELOG entry

.git_archival.txt

@@ -0,0 +1,4 @@
+node: $Format:%H$
+node-date: $Format:%cI$
+describe-name: $Format:%(describe:tags=true)$
+ref-names: $Format:%D$

CHANGELOG.rst

@@ -67,7 +67,9 @@ Internal Changes
   By `Mathias Hauser <https://github.com/mathause>`_.
 - Move contents of setup.py to setup.cfg (`#169 <https://github.com/MESMER-group/mesmer/pull/169>`_).
   By `Mathias Hauser <https://github.com/mathause>`_.
-
+- Use pyproject.toml for the build-system and setuptools_scm for the `__version__`
+  (`#188 <https://github.com/MESMER-group/mesmer/pull/188>`_).
+  By `Mathias Hauser <https://github.com/mathause>`_.
 
 v0.8.3 - 2021-12-23
 -------------------

MANIFEST.in

@@ -1,6 +1,3 @@
 include README.md
 include LICENSE
 include CHANGELOG.rst
-
-include versioneer.py
-include mesmer/_version.py

docs/source/conf.py

@@ -8,22 +8,24 @@
 
 import datetime
 
-from mesmer._version import get_versions
+import mesmer
 
 # -- Project information -----------------------------------------------------
 
 project = "mesmer"
 copyright_year = datetime.date.today().year
-copyright = "(c) 2021-{} ETH Zurich (Land-climate dynamics group, Prof. S.I. Seneviratne), MESMER contributors listed in AUTHORS".format(
-    copyright_year
+copyright = (
+    f"(c) 2021-{copyright_year} ETH Zurich (Land-climate dynamics group, Prof. S.I. "
+    "Seneviratne), MESMER contributors listed in AUTHORS"
 )
+
 authors = "Authors, see AUTHORS"
 author = authors
 
 # The short X.Y version
-version = get_versions()["version"].split("+")[0]
+version = mesmer.__version__.split("+")[0]
 # The full version, including alpha/beta/rc tags
-release = get_versions()["version"]
+release = mesmer.__version__
 
 
 # -- General configuration ---------------------------------------------------

mesmer/__init__.py

@@ -6,11 +6,21 @@
 The mesmer package provides tools to train the MESMER emulator, create emulations, and
 analyze the results.
 """
-from ._version import get_versions
-
-__version__ = get_versions()["version"]
-del get_versions
-
 # flake8: noqa
 
 from . import calibrate_mesmer, create_emulations, io, utils
+
+try:
+    from importlib.metadata import version as _get_version
+except ImportError:
+    # importlib.metadata not available in python 3.7
+    import pkg_resources
+
+    _get_version = lambda pkg: pkg_resources.get_distribution(pkg).version
+
+try:
+    __version__ = _get_version("mesmer-emulator")
+except Exception:
+    # Local copy or not installed with setuptools.
+    # Disable minimum version checks on downstream libraries.
+    __version__ = "999"