python3变量类型声明语法错误

Question

为什么:语法不能在linux上工作？

On MacOS

→ python3
Python 3.6.3 (default, Oct  4 2017, 06:09:38) 
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.37)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> x : str = "hello"
>>> 

On Linux

→ python3
Python 3.5.3 (default, Jan 19 2017, 14:11:04) 
[GCC 6.3.0 20170118] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> x : str = "hello"
  File "<stdin>", line 1
    x : str = "hello"
      ^
SyntaxError: invalid syntax
>>> 

Answer 1

导致这种情况的是python的版本。在Linux上也更新到3.6。核对发布说明

3.6版有什么新鲜事

Answer 2

这是python版本的问题所在。在linux中对3.6进行同样的尝试。