# Jupyter Display Playground
Nextjournal’s Jupyter runtimes now fully support all of Jupyter’s [display kernel messages](https://jupyter-client.readthedocs.io/en/stable/messaging.html#display-data). Remix this notebook to try them out yourself.
This notebook already uses a *Python Jupyter runtime*. You can select a runtime’s type (e.g. Jupyter or Nextjournal) via the *runtime settings menu* (available from the sidebar or from the runtimes section listed at the bottom of this document).
# Showing multiple results
Let’s start by running this cell to import `IPython.display` and also `numpy` for some of the following examples:
```python id=94751a7e-f3f7-44b4-93f6-f2c5fbe9354c
from IPython.display import display, HTML, Audio
import numpy as np
```
As you run the next cell, you will see that calling [`display`](https://ipython.readthedocs.io/en/stable/api/generated/IPython.display.html#IPython.display.display) multiple times (each time passing a rich media/MIME bundle object) will stack corresponding results below the cell:
```python id=1ca7868b-0e57-4498-8317-7ea7e676a01e
dynamite = "🧨
"
display(HTML(dynamite))
d1 = display(HTML(dynamite), display_id=True)
d2 = display(HTML(dynamite), display_id=True)
sample_rate=44100
noise = np.random.normal(0, 1, size=sample_rate)
display(Audio(noise, rate=sample_rate))
'✅ last return will also be shown as last result'
```
# Updating results
In addition to that, we also support changing display objects in place by calling `update` on the [display handle](https://ipython.readthedocs.io/en/stable/api/generated/IPython.display.html#IPython.display.DisplayHandle). Note that, when running the following cell, the last 🧨 from the above cell’s results will turn into a 💥.
```python id=1d0aceb4-465c-4f64-af81-ac3a22c9d6c3
import time
time.sleep(0.5)
d2.update(HTML("💥
"))
```
To demonstrate a more elaborate version of this, let’s implement *[Conway's Game of Life](http://en.wikipedia.org/wiki/Conway%27s_Game_of_Life)* based on code by [@gvwilson](http://twitter.com/gvwilson) & [@jiffyclub](https://twitter.com/jiffyclub).
First, let’s set up a function that draws the cells:
```python id=104bf0ba-43c9-44d6-a015-7b8bee506e27
def board2html(board):
nx, ny = board.shape
table = '\n'
for y in range(ny-1, -1, -1):
table += ''
for x in range(0, nx):
if board[x, y]:
table += ' | '
else:
table += ' | '
table += '
\n'
table += '
'
return table
```
We will also need functions to evolve and advance the cells based on their neighbours:
```python id=169d4032-1b44-471a-9e48-5288710e32be
import time
def evolve(length, generations):
current = np.random.randint(2, size=(length, length))
next = np.empty_like(current)
h = display(HTML(board2html(current)), display_id=True)
for _ in range(generations):
advance(current, next)
current, next = next, current
h.update(HTML(board2html(current)))
time.sleep(0.5)
```
```python id=a25d1279-9a38-47e1-bfeb-246e1fd2f482
from scipy.signal import convolve
# used for counting the number of living neighbors each cell has
FILTER = np.array([[1, 1, 1],
[1, 100, 1],
[1, 1, 1]], dtype=np.uint8)
def advance(current, next):
assert current.shape[0] == current.shape[1], 'Expected square universe'
next[:] = 0
count = convolve(current, FILTER, mode='same')
next[(count == 3) | (count == 102) | (count == 103)] = 1
```
And finally, let’s call evolve to draw the evolution:
```python id=2aeeb1a5-bcdc-4b60-a460-5ec1a595a5d2
evolve(30, 20)
```
That’s it for now. You can read up on Jupyter’s kernel display messages in the [Project Jupyter Docs](https://jupyter-client.readthedocs.io/en/stable/messaging.html#display-data) and if you have feedback for us, please [get in touch](#intercom)!
This notebook was exported from https://nextjournal.com/a/MFXzU9rygYcZX8AAg2kJh?change-id=CuJDUfvhCfLZXXcAbX45y6
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