This extension allows dynamically displaying Python variables in markdown cells.
For example:
If you set variable a in Python
a = 1.23
and write the following line in a markdown cell:
a = {{a}}
It will be displayed as:
a = 1.23
Further examples
Before rendering the markdown cell:
After rendering the markdown cell:
Python code is only executed when the notebook is trusted. So if your original Python code is still shown in rendered markdown output, please make sure your notebook is trusted.
Caution: There is no restriction in the expression you can embedd in {{ }}. Be careful as you might crash your browser if you return too large datasets.
Also, images in markdown will be removed due to the HTML sanitizer after a reload.
Installation
Install the master version of the IPython-notebook-extensions repository as explained on the main wiki page.
Then load the extension from within the IPython notebook:
%%javascript
IPython.load_extensions('usability/python-markdown/main');
In order to have nbconvert show the preprocessed output, copy the pymdpreprocessor.py file to a location in your PYTHONPATHand add or extend the following line to your ipython_nbconvert_config.py configuration file:
c.Exporter.preprocessors = [ 'pymdpreprocessor.PyMarkdownPreprocessor' ]
Internals
The extension overrides the textcell.MarkdownCell.prototype.render function and searches for a Python expression enclosed in double curly braced {{ <expr> }}. It then executes the expression and replaces it with the result returned from Python, embedded in a <span> tag.
Additionally, the result is saved in the metadata of the markdown cell, i.e. cell.metadata.variables[varname]. This stored value is displayed when reloading the notebook and used for the nbconvert preprocesser.
The preprocessor pymdpreprocessor.PyMarkdownPreprocessor allows nbconvert to display the computed variables when converting the notebook to an output file format.