Implement Python package versioning (#174)

* advice from @gsakkis

* .gitignore file

* black .

* Clarifying comments

.gitignore

@@ -46,5 +46,6 @@ examples/cmake_project/build
 # Python distribution / packaging
 .eggs
 *.egg-info
+apis/python/src/tiledbsc/_version.py
 
 /.quarto/

apis/python/pyproject.toml

@@ -6,3 +6,11 @@ requires = [
     "pybind11>=2.6.2"
 ]
 build-backend = "setuptools.build_meta"
+
+[tool.setuptools_scm]
+version_scheme = "guess-next-dev"
+local_scheme = "dirty-tag"
+# Relative path to cwd, used for finding the SCM root
+root = "../.."
+# Path relative to root to a file that gets replaced with a file containing the current version
+write_to = "apis/python/src/tiledbsc/_version.py"

apis/python/setup.cfg

@@ -51,8 +51,3 @@ ci =
     pytest
     anndata
     pybind11
-
-[tool.setuptools_scm]
-version_scheme = guess-next-dev
-local_scheme = dirty-tag
-write_to = ./version.py

apis/python/src/tiledbsc/__init__.py

@@ -1,3 +1,36 @@
+# The way this works is:
+#
+# o We put a `[tool.setuptools_scm]` stanza in pyproject.toml.
+#
+# o When the user does `pip install .` the src/tiledbsc/_version.py
+#   file gets created. We have a .gitignore line for that since it
+#   isn't supposed to go into version control, but rather, is supposed
+#   to be created at package-setup time.
+#
+# o The src/tiledbsc/_version.py is created by setuptools by reading
+#   Git history. If the currently checked-out code is at a version stamp
+#   like `1.2.3` we'll get `__version__` being `1.2.3`; else we'll get
+#   something like `1.2.4.dev2`.
+#
+# o When the user does `import tiledbsc` this code here is run,
+#   which loads the `src/tiledbsc/_version.py`.
+#
+# In summary, who needs to do what:
+#
+# o Package developers: simply create a Git release at
+# https://github.com/single-cell-data/TileDB-SingleCell/releases
+#
+# o Package users: just `pip install .`.
+try:
+    from ._version import version as __version__
+except ImportError:
+    from pkg_resources import DistributionNotFound, get_distribution
+
+    try:
+        __version__ = get_distribution("tiledbsc").version
+    except DistributionNotFound:
+        __version__ = "unknown"
+
 from .soma_collection import SOMACollection
 from .soma import SOMA
 from .soma_options import SOMAOptions