我尝试运行 IPython 笔记本。我在命令行中输入了以下内容：
ipython 笔记本
我收到以下错误（堆栈跟踪）
> Traceback (most recent call last): File
> "C:\Python27\Scripts\ipython-script.py", line 9, in <module>
> load_entry_point('ipython==0.13.1', 'console_scripts', 'ipython')() File
> "C:\Python27\lib\site-packages\IPython\frontend\terminal\ipapp.py",
> line 388, in launch_new_instance
> app.initialize() File "<string>", line 2, in initialize File "C:\Python27\lib\site-packages\IPython\config\application.py", line
> 84, i n catch_config_error
> return method(app, *args, **kwargs) File "C:\Python27\lib\site-packages\IPython\frontend\terminal\ipapp.py",
> line 313, in initialize
> super(TerminalIPythonApp, self).initialize(argv) File "<string>", line 2, in initialize File
> "C:\Python27\lib\site-packages\IPython\config\application.py", line
> 84, i n catch_config_error
> return method(app, *args, **kwargs) File "C:\Python27\lib\site-packages\IPython\core\application.py", line 325,
> in initialize
> self.parse_command_line(argv) File "C:\Python27\lib\site-packages\IPython\frontend\terminal\ipapp.py",
> line 308, in parse_command_line
> return super(TerminalIPythonApp, self).parse_command_line(argv) File "<string>", line 2, in parse_command_line File
> "C:\Python27\lib\site-packages\IPython\config\application.py", line
> 84, i n catch_config_error
> return method(app, *args, **kwargs) File "C:\Python27\lib\site-packages\IPython\config\application.py", line
> 420, in parse_command_line
> return self.initialize_subcommand(subc, subargv) File "<string>", line 2, in initialize_subcommand File
> "C:\Python27\lib\site-packages\IPython\config\application.py", line
> 84, i n catch_config_error
> return method(app, *args, **kwargs) File "C:\Python27\lib\site-packages\IPython\config\application.py", line
> 352, in initialize_subcommand
> subapp = import_item(subapp) File "C:\Python27\lib\site-packages\IPython\utils\importstring.py", line
> 40, i n import_item
> module = __import__(package,fromlist=[obj]) File "C:\Python27\lib\site-packages\IPython\frontend\html\notebook\__init__.py
> ", line 8, in <module>
> raise ImportError(msg) ImportError: The IPython Notebook requires tornado >= 2.1.0
我该如何解决？我有 Python 2.7 版