获取ipython notebook filename的功能

Question

此代码在Ipython / Juypter单元格中正常工作以获取笔记本文件名：

js = """var kernel = IPython.notebook.kernel;
var thename = window.document.getElementById("notebook_name").innerHTML;
var command = "theNotebook2 = " + "'"+thename+"'";
kernel.execute(command);"""
display(Javascript(js))
theNotebook2 + '.ipynb'

'techela.ipynb'

如果我在单元格中定义一个函数并调用它：

def get_filename():
    """Get the notebook filename."""
    js = """var kernel = IPython.notebook.kernel;
var thename = window.document.getElementById("notebook_name").innerHTML;
var command = "theNotebook2 = " + "'"+thename+"'";
kernel.execute(command);"""
    display(Javascript(js))
    return theNotebook2 + '.ipynb'

get_filename()

'techela.ipynb'

它似乎工作正常，并给我文件名。

但是，如果我将该功能放入模块中并导入它，那么它就会停止工作。

from techela import get_filename
get_filename()
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-17-42ee37d0d253> in <module>()
      1 from techela import get_filename
----> 2 get_filename()

/Users/jkitchin/techela/ipynb/techela.py in get_filename()
     11 kernel.execute(command);"""
     12     display(Javascript(js))
---> 13     return theNotebook2 + '.ipynb'
     14 
     15 

NameError: name 'theNotebook2' is not defined

知道为什么会失败吗？