[MRG] use setuptools_scm for version management (#471)

* Use setuptools_scm for versioning

- add setuptools_scm_git_archive support
- update release docs

* update setuptools_scm

* fix variable name

.git_archival.txt

@@ -0,0 +1 @@
+ref-names: $Format:%D$

.gitattributes

@@ -0,0 +1 @@
+.git_archival.txt  export-subst

.gitignore

@@ -19,3 +19,8 @@ _minhash.so
 .coverage
 sourmash_lib/_minhash.cpp
 sourmash/_minhash.cpp
+.asv/
+.eggs/
+.pytest_cache
+.python-version
+sourmash/version.py

Makefile

@@ -35,4 +35,7 @@ wheel:
 	docker pull $${DOCKER_IMAGE} ; \
 	docker run --rm -v `pwd`:/io $${DOCKER_IMAGE} /io/travis/build-wheels.sh
 
+last-tag:
+	git fetch -p -q; git tag -l | sort -V | tail -1
+
 FORCE:

doc/release.md

@@ -27,7 +27,7 @@ cd sourmash
  and then tag the release candidate with the new version number prefixed by
    the letter 'v':
 ```
-        git tag v${new_version}-${rc}
+        git tag -a v${new_version}-${rc}
         git push --tags git@github.com:dib-lab/sourmash.git
 ```
 3\. Test the release candidate. Bonus: repeat on Mac OS X:
@@ -116,7 +116,7 @@ so:
    authorized account):
 ```
         cd ../sourmash
-        git tag v${new_version}
+        git tag -a v${new_version}
         python setup.py register sdist upload
 ```
 2\. Delete the release candidate tag and push the tag updates to GitHub:

setup.py

@@ -4,11 +4,6 @@
 from setuptools import Extension
 import os
 
-# retrieve VERSION from sourmash/VERSION.
-thisdir = os.path.dirname(__file__)
-version_file = open(os.path.join(thisdir, 'sourmash', 'VERSION'))
-VERSION = version_file.read().strip()
-
 EXTRA_COMPILE_ARGS = ['-std=c++11', '-pedantic']
 EXTRA_LINK_ARGS=[]
 
@@ -48,7 +43,6 @@
 SETUP_METADATA = \
                {
     "name": "sourmash",
-    "version": VERSION,
     "description": "tools for comparing DNA sequences with MinHash sketches",
     "long_description": LONG_DESCRIPTION,
     "long_description_content_type": "text/markdown",
@@ -71,7 +65,9 @@
                                extra_compile_args=EXTRA_COMPILE_ARGS,
                                extra_link_args=EXTRA_LINK_ARGS)],
     "install_requires": ["screed>=0.9", "ijson", "khmer>=2.1"],
-    "setup_requires": ['Cython>=0.25.2', "setuptools>=38.6.0"],
+    "setup_requires": ['Cython>=0.25.2', "setuptools>=38.6.0",
+                       'setuptools_scm', 'setuptools_scm_git_archive'],
+    "use_scm_version": {"write_to": "sourmash/version.py"},
     "extras_require": {
         'test' : ['pytest', 'pytest-cov', 'numpy', 'matplotlib', 'scipy','recommonmark'],
         'demo' : ['jupyter', 'jupyter_client', 'ipython'],

sourmash/__init__.py

@@ -20,7 +20,15 @@
 from . import sbt_storage
 from . import signature
 
-# retrieve VERSION from sourmash/VERSION.
-thisdir = os.path.dirname(__file__)
-version_file = open(os.path.join(thisdir, 'VERSION'))
-VERSION = version_file.read().strip()
+from pkg_resources import get_distribution, DistributionNotFound
+try:
+    VERSION = get_distribution(__name__).version
+except DistributionNotFound:  # pragma: no cover
+    try:
+        from .version import version as VERSION  # noqa
+    except ImportError:  # pragma: no cover
+        raise ImportError(
+            "Failed to find (autogenerated) version.py. "
+            "This might be because you are installing from GitHub's tarballs, "
+            "use the PyPI ones."
+        )