add compatibility to readme

README.md

@@ -5,6 +5,12 @@
 
 对应的 REST API 文档：<http://docs.jpush.io/server/rest_api_v3_push/>
 
+## 兼容版本
+Python 2.7
+Python 3 还没有兼容，以后会兼容。
+建议 Python3 的开发者继续使用 jpush 3.1.2，pip 地址：
+>   https://pypi.python.org/pypi?:action=display&name=jpush&version=3.1.2
+
 ## 环境配置
 
 pip 方式：

examples/push_examples/example_all.py

@@ -18,6 +18,6 @@ except common.Unauthorized:
 except common.APIConnectionException:
     raise common.APIConnectionException("conn")
 except common.JPushFailure:
-    print "JPushFailure"
+    print ("JPushFailure")
 except:
-    print "Exception"
+    print ("Exception")
\ No newline at end of file

jpush/core.py

@@ -72,7 +72,7 @@ class JPush(object):
             if (level == "NOTSET"):
                 logging.basicConfig(level=logging.NOTSET)
         else:
-            print "set logging level failed ,the level is invalid."
+            print ("set logging level failed ,the level is invalid.")
 
     def create_push(self):
         """Create a Push notification."""