BUG: Fix for cython version checking pandas-dev#9827

Author: ajamian

setup.py

@@ -11,13 +11,21 @@
 import shutil
 import warnings
 import re
+from distutils.version import LooseVersion
 
 # may need to work around setuptools bug by providing a fake Pyrex
+min_cython_ver = '0.19.1'
 try:
     import Cython
     sys.path.insert(0, os.path.join(os.path.dirname(__file__), "fake_pyrex"))
+    ver = Cython.__version__
+    _CYTHON_INSTALLED = ver >= LooseVersion(min_cython_ver)
+    print 'cython version %s' % ver # NOTE: TA DEBUG
+#    _CYTHON_INSTALLED = True
+#    if not _CYTHON_INSTALLED:
+#        sys.exit('Install requires Cython >= %s' % min_cython_ver)
 except ImportError:
-    pass
+    _CYTHON_INSTALLED = False
 
 # try bootstrapping setuptools if it doesn't exist
 try:
@@ -74,6 +82,8 @@
 from distutils.command.build_ext import build_ext as _build_ext
 
 try:
+    if not _CYTHON_INSTALLED:
+        raise ImportError('No supported version of Cython installed.')
     from Cython.Distutils import build_ext as _build_ext
     # from Cython.Distutils import Extension # to get pyrex debugging symbols
     cython = True