Standardize version number placement

codejail/__init__.py

@@ -0,0 +1,3 @@
+"""init"""
+
+__version__ = '3.1.5'

setup.py

@@ -1,13 +1,33 @@
 """CodeJail: manages execution of untrusted code in secure sandboxes."""
+import os
+import re
 
 from setuptools import setup
 
 with open('README.rst') as readme:
     long_description = readme.read()
 
+
+def get_version(*file_paths):
+    """
+    Extract the version string from the file at the given relative path fragments.
+    """
+    filename = os.path.join(os.path.dirname(__file__), *file_paths)
+    with open(filename, encoding='utf-8') as opened_file:
+        version_file = opened_file.read()
+        version_match = re.search(r"^__version__ = ['\"]([^'\"]*)['\"]",
+                                  version_file, re.M)
+    if version_match:
+        return version_match.group(1)
+    raise RuntimeError('Unable to find version string.')
+
+
+VERSION = get_version("codejail", "__init__.py")
+
+
 setup(
     name="edx-codejail",
-    version="3.1.5",
+    version=VERSION,
     license='Apache',
     description='CodeJail manages execution of untrusted code in secure sandboxes. It is designed primarily for '
                 'Python execution, but can be used for other languages as well.',