1 files changed, 104 insertions, 0 deletions
diff --git a/pkg/version.py b/pkg/version.py
new file mode 100644
index 00000000..aa872b29
--- /dev/null
+++ b/pkg/version.py
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+# -*- coding: utf-8 -*-
+# Author: Douglas Creager <dcreager@dcreager.net>
+# This file is placed into the public domain.
+
+# Calculates the current version number.  If possible, this is the
+# output of “git describe”, modified to conform to the versioning
+# scheme that setuptools uses.  If “git describe” returns an error
+# (most likely because we're in an unpacked copy of a release tarball,
+# rather than in a git working copy), then we fall back on reading the
+# contents of the RELEASE-VERSION file.
+#
+# To use this script, simply import it your setup.py file, and use the
+# results of get_git_version() as your package version:
+#
+# from version import *
+#
+# setup(
+#     version=get_git_version(),
+#     .
+#     .
+#     .
+# )
+#
+# This will automatically update the RELEASE-VERSION file, if
+# necessary.  Note that the RELEASE-VERSION file should *not* be
+# checked into git; please add it to your top-level .gitignore file.
+#
+# You'll probably want to distribute the RELEASE-VERSION file in your
+# sdist tarballs; to do this, just create a MANIFEST.in file that
+# contains the following line:
+#
+#   include RELEASE-VERSION
+
+__all__ = ("get_git_version")
+
+from subprocess import Popen, PIPE
+
+
+def call_git_describe(abbrev=4):
+    try:
+        p = Popen(['git', 'describe', '--abbrev=%d' % abbrev],
+                  stdout=PIPE, stderr=PIPE)
+        p.stderr.close()
+        line = p.stdout.readlines()[0]
+        return line.strip()
+
+    except:
+        return None
+
+
+def read_release_version():
+    try:
+        f = open("pkg/RELEASE_VERSION", "r")
+
+        try:
+            version = f.readlines()[0]
+            return version.strip()
+
+        finally:
+            f.close()
+
+    except:
+        return None
+
+
+def write_release_version(version):
+    f = open("pkg/RELEASE_VERSION", "w")
+    f.write("%s\n" % version)
+    f.close()
+
+
+def get_git_version(abbrev=4):
+    # Read in the version that's currently in RELEASE-VERSION.
+
+    release_version = read_release_version()
+
+    # First try to get the current version using “git describe”.
+
+    version = call_git_describe(abbrev)
+
+    # If that doesn't work, fall back on the value that's in
+    # RELEASE-VERSION.
+
+    if version is None:
+        version = release_version
+
+    # If we still don't have anything, that's an error.
+
+    if version is None:
+        raise ValueError("Cannot find the version number!")
+
+    # If the current version is different from what's in the
+    # RELEASE-VERSION file, update the file to be current.
+
+    if version != release_version:
+        write_release_version(version)
+
+    # Finally, return the current version.
+
+    return version
+
+
+if __name__ == "__main__":
+    print get_git_version()