Merge 564a647 into 588cad5

chainer/_environment_check.py

@@ -22,6 +22,19 @@ def _check_python_350():
             raise Exception(msg)
 
 
+def _check_python_2():
+    if sys.version_info[:1] == (2,):
+        warnings.warn('''
+--------------------------------------------------------------------------------
+Chainer is going to stop supporting Python 2 in v7.x releases.
+
+Future releases of Chainer v7.x will not run on Python 2.
+If you need to continue using Python 2, consider using Chainer v6.x, which
+will be the last version that runs on Python 2.
+--------------------------------------------------------------------------------
+''')  # NOQA
+
+
 def _check_osx_numpy_backend():
     if sys.platform != 'darwin':
         return
@@ -91,6 +104,7 @@ def _check_optional_dependencies():
 
 
 def check():
+    _check_python_2()
     _check_python_350()
     _check_osx_numpy_backend()
     _check_optional_dependencies()