Jupyter Notebook Enhancements, Tips And Tricks

(深度碎片) #28

How to create a multi-line code snippet for Jupyter notebook

First, install nbextensions

conda install jupyter_contrib_nbextensions
jupyter contrib nbextension install --user

Second, go to your jupyter notebook and open nbextensions settings to add features


Third, open custom.js file and add the following codes

require(["nbextensions/snippets_menu/main"], function (snippets_menu) {
        console.log('Loading `snippets_menu` customizations from `custom.js`');
        var horizontal_line = '---';
        var my_favorites = {
        'name' : 'My favorites',
        'sub-menu' : [
                      {
                      'name' : 'most_jupyter_magics',
                      'snippet' : ['%reload_ext autoreload',
                                   '%autoreload 2',
                                   '%matplotlib inline',
                                   'from IPython.core.interactiveshell import InteractiveShell',
                                   'InteractiveShell.ast_node_interactivity = "all"',],
                      },
                      {
                      'name' : 'kaggle download links',
                      'snippet' : ['from IPython.display import FileLinks',
                                   'FileLinks(\'.\')',],
                      },
                      {
                      'name' : 'details_drop',
                      'snippet' : ['[/details][details=""]',],
                      },
                      {
                      'name' : 'find snippet custom js',
                      'snippet' : ['echo $(jupyter --config-dir)/custom/custom.js',],
                      },
                      ],
        };
        snippets_menu.options['menus'].push(snippets_menu.default_menus[0]);
        snippets_menu.options['menus'][0]['sub-menu'].push(horizontal_line);
        snippets_menu.options['menus'][0]['sub-menu'].push(my_favorites);
        console.log('Loaded `snippets_menu` customizations from `custom.js`');
        });

Finally, refresh your notebook page, and you shall see the following


reference:
Jupyter docs on snippet

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Fast.ai v3 2019课程中文版笔记
(Stas Bekman) #29

Getting the notebook name automatically

# cell 1
%%javascript
IPython.notebook.kernel.execute('nb_name = ' + '"' + IPython.notebook.notebook_name + '"')
# cell 2
nb_name

Same without js magic:

# cell 1
from IPython.display import display, Javascript
Javascript("IPython.notebook.kernel.execute('nb_name = ' + '\"' + IPython.notebook.notebook_name + '\"')")
# cell 2
nb_name

In either case, JS is async - so it may not run right away and therefore it’s not guaranteed nb_name will be set right away.

I was looking for this feature, since I wanted to replace hardcoded cells in each dev_nbs such as:

!./notebook2script.py 02_fully_connected.ipynb

with something similar that will extract the nb name automatically.

So I wrote a little helper function:

from IPython.display import display, Javascript
def nb_auto_export():
    display(Javascript("if (IPython.notebook.kernel) {IPython.notebook.kernel.execute('!./notebook2script.py ' + IPython.notebook.notebook_name )}"))

(it looks like JS is the only way to get the nb name in jupyter :frowning:)

notes:

  • it assumes the nb name has no spaces in it, add quotes if it does
  • had to bracket the code with if (IPython.notebook.kernel) {} since the browser will attempt to run this js code automatically on jupyter nb load and fail, since IPython.notebook.kernel hasn’t been defined yet. It only happens if there is ! in the js code - odd.

and now there is no need to hardcode the nb name, just have the last cell say:

nb_auto_export()

that is if you imported nb_auto_export from somewhere you saved it.

Or alternatively without needing to import anything, you could just have the last cell of each notebook:

%%javascript 
if (IPython.notebook.kernel) {
    IPython.notebook.kernel.execute('!./notebook2script.py ' + IPython.notebook.notebook_name)
}

Also note that it’s async, so it usually takes a sec or so to start running once the nb finished running.

Or the messier approach w/o js magic:

from IPython.display import display, Javascript
display(Javascript("if (IPython.notebook.kernel) {IPython.notebook.kernel.execute('!./notebook2script.py ' + IPython.notebook.notebook_name)}"))

You might be able to drop display from it, but it seems not to work w/o it for me.

Finally, you shouldn’t rely on auto-save, since you’re likely to miss recent changes, so why not tell this code to save the notebook first, resulting in this code:

from IPython.display import display, Javascript
def nb_auto_export():
    display(Javascript("if (IPython.notebook) { IPython.notebook.save_notebook() }; if (IPython.notebook.kernel) { IPython.notebook.kernel.execute('!./notebook2script.py  ' + IPython.notebook.notebook_name )}"))

Ideas for this solution came from SO: 1, 2

2 Likes

Lesson 9 Discussion & Wiki (2019)
(Thomas) #30

With a bit of Python import glue, you could also skip the export step and just import the notebooks (I used a %lib magic to indicate the things actually I want to show up in the library, but you could remove that and take it all). Maybe that can be even more user friendly than having to export things.

Best regards

Thomas

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(Bart Fish) #31

Interactive Labeling:

I have some python code that I would like to use for interactive labeling of sections in a matplotlib plot using Jupyter Notebook. The code seems to work in python 2.7 under GUI, but will not run properly in a notebook. The problem is that the matplotlib close_event never leaves the cell containing the plot.

I’ve put together an example to demonstrate. If anyone has some working Jupyter Notebook code that can be used to label sections of a plot interactively please let me know.

Here is the sample code:

The notebook is here

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(Stas Bekman) #32

Please do not use this thread for questions or problem reports, instead post them here:


as explained in the first post. Thank you.

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(nok) #33

AutoScroll and go to current cell function are now included in the extension. The extension is in master branch but a new pip version is not released yet.

For now, you can install through

pip install https://github.com/ipython-contrib/jupyter_contrib_nbextensions/tarball/master

The PR for go to current cell

You can customize the shortkey yourself if needed.

1 Like

(Stas Bekman) #34

Undo cell delete

2 Likes