thebe.md

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Make your code cells executable

This section describes how to bring interactivity to your book. This lets users run code and see outputs without leaving the page. Interactivity is provided by a kernel running on the public MyBinder service.

For an example, click the {fa}rocket --> {guilabel}Live Code button above on this page, and run the code below.

import numpy as np
import matplotlib.pyplot as plt
plt.ion()

x = np.arange(500)
y = np.random.randn(500)

fig, ax = plt.subplots()
ax.scatter(x, y, c=y, s=x)

:::{warning} This is an experimental feature, and may change in the future or work unexpectedly. :::

Pre-execute cells when Thebe is initialized

Sometimes you'd like to run some code cells immediately when a kernel is requested. This might be code that you then hide from the user in order to narrow the focus of what they interact with. This is possible by using cell tags for the Jupyter Notebook.

Adding the tag {guilabel}thebe-init to any code cell will cause Thebe to run this cell after it has received a kernel. Any subsequent Thebe cells will have access to the same environment (e.g. any module imports made in the initialization cell).

You can then pair this with something like {guilabel}hide-input in order to run initialization code that your user doesn't immediately see. For example, below we'll initialize a variable in a hidden cell, and then tell another cell to print the output of that variable.

:tags: [hide-input, thebe-init]

my_hidden_variable = 'wow, it worked!'

# The variable for this is defined in the cell above!
print(my_hidden_variable)