[Core] Add dynamic versioning based on git tag (#790)

core/__init__.py

@@ -1 +1,37 @@
-from core.config import Config
+from core.config import Config
+from subprocess import run, PIPE
+from collections import namedtuple
+
+__all__ = ["Config", "__version__"]
+version_info = namedtuple("VersionInfo", "major minor patch")
+
+BASE_VERSION = version_info(3, 0, 0)
+
+
+def get_latest_version():
+    try:
+        p = run(
+            "git describe --abbrev=0 --tags".split(),
+            stdout=PIPE
+        )
+    except FileNotFoundError:
+        # No git
+        return BASE_VERSION
+
+    if p.returncode != 0:
+        return BASE_VERSION
+
+    stdout = p.stdout.strip().decode()
+    if stdout.startswith("v"):
+        numbers = stdout[1:].split('.')
+        args = [0, 0, 0]
+        for i in range(3):
+            try:
+                args[i] = int(numbers[i])
+            except (IndexError, ValueError):
+                args[i] = 0
+        return version_info(*args)
+    return BASE_VERSION
+
+__version__ = get_latest_version()
+

tests/core/test_version.py

@@ -0,0 +1,6 @@
+import core
+
+
+def test_version_working():
+    assert hasattr(core, '__version__')
+    assert core.__version__ >= (3, 0, 0)