Get version number from git

Author: ljosa

.gitignore

@@ -3,3 +3,4 @@
 /docs/_build
 /python_bioformats.egg-info
 /dist
+/bioformats/_version.py

bioformats/__init__.py

@@ -8,7 +8,12 @@
 '''Bioformats package - wrapper for loci.bioformats java code
 
 '''
-__version__ = "$Revision$"
+
+try:
+    from _version import __version__
+except ImportError:
+    # We're running in a tree that doesn't have a _version.py, so we don't know what our version is.
+    __version__ = "0.0.0"
 
 import os.path
 import javabridge

setup.py

@@ -1,8 +1,48 @@
+import os.path
+import re
+import subprocess
 from setuptools import setup, find_packages
 
+def get_version():
+    """Get version from git or file system.
+
+    If this is a git repository, try to get the version number by
+    running ``git describe``, then store it in
+    bioformats/_version.py. Otherwise, try to load the version number
+    from that file. If both methods fail, quietly return None.
+
+    """
+    git_version = None
+    if os.path.exists(os.path.join(os.path.dirname(__file__), '.git')):
+        import subprocess
+        try:
+            git_version = subprocess.check_output(['git', 'describe']).strip()
+        except:
+            pass
+
+    version_file = os.path.join(os.path.dirname(__file__), 'bioformats', 
+                                '_version.py')
+    if os.path.exists(version_file):
+        with open(version_file) as f:
+            cached_version_line = f.read().strip()
+        try:
+            # From http://stackoverflow.com/a/3619714/17498
+            cached_version = re.search(r"^__version__ = ['\"]([^'\"]*)['\"]", 
+                                       cached_version_line, re.M).group(1)
+        except:
+            raise RuntimeError("Unable to find version in %s" % version_file)
+    else:
+        cached_version = None
+
+    if git_version and git_version != cached_version:
+        with open(version_file, 'w') as f:
+            print >>f, '__version__ = "%s"' % git_version
+
+    return git_version or cached_version
+
 setup(
     name="python-bioformats",
-    version="1.0.0pr3",
+    version=get_version(),
     description="Read and write life sciences file formats",
     long_description='''Python-bioformats is a Python wrapper for Bio-Formats, a standalone
     Java library for reading and writing life sciences image file