From fb6ac28b44947c74600d09ff2231bc0d1987537d Mon Sep 17 00:00:00 2001
From: xutianming <tianmingxu.tmxu@gmail.com>
Date: Mon, 5 Nov 2018 05:53:55 +0800
Subject: [PATCH] single sourcing the package version (#3220)

---
 python/ray/__init__.py |  3 +--
 python/setup.py        | 15 +++++++++++++--
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/python/ray/__init__.py b/python/ray/__init__.py
index 95255bba1..a507cdd2e 100644
--- a/python/ray/__init__.py
+++ b/python/ray/__init__.py
@@ -61,8 +61,7 @@ import ray.internal  # noqa: E402
 import ray.actor  # noqa: F401
 from ray.actor import method  # noqa: E402
 
-# Ray version string. TODO(rkn): This is also defined separately in setup.py.
-# Fix this.
+# Ray version string.
 __version__ = "0.5.3"
 
 __all__ = [
diff --git a/python/setup.py b/python/setup.py
index e55cc2529..bd0ef97a6 100644
--- a/python/setup.py
+++ b/python/setup.py
@@ -3,6 +3,7 @@ from __future__ import division
 from __future__ import print_function
 
 import os
+import re
 import shutil
 import subprocess
 import sys
@@ -118,10 +119,20 @@ class BinaryDistribution(Distribution):
         return True
 
 
+def find_version(*filepath):
+    # Extract version information from filepath
+    here = os.path.abspath(os.path.dirname(__file__))
+    with open(os.path.join(here, *filepath)) as fp:
+        version_match = re.search(r"^__version__ = ['\"]([^'\"]*)['\"]",
+                                  fp.read(), re.M)
+        if version_match:
+            return version_match.group(1)
+        raise RuntimeError("Unable to find version string.")
+
+
 setup(
     name="ray",
-    # The version string is also in __init__.py. TODO(pcm): Fix this.
-    version="0.5.3",
+    version=find_version("ray", "__init__.py"),
     description=("A system for parallel and distributed Python that unifies "
                  "the ML ecosystem."),
     long_description=open("../README.rst").read(),