Altair charts in juypter notebook does not render - python-2.7

Question

I can't figure out what's up in my jupyter notebook. Vincent and Bokeh work fine, but in trying out Altair, I must be missing something, but I'm not erroring and the online docs don't mention my problem.
This is what I enter (from documentation page https://altair-viz.github.io/gallery/bar_aggregate.html )
from altair import *
Chart('http://vega.github.io/vega-lite/data/population.json',
description='A bar chart showing the US population distribution of age groups in 2000.',
).mark_bar().encode(
x=X('sum(people):Q',
axis=Axis(
title='population',
),
),
y=Y('age:O',
scale=Scale(
bandSize=17.0,
),
),
).transform_data(
filter='datum.year == 2000',
)
The code executes in my Jupyter notebook with no errors, but also no graph. I do have vega installed, so that's not the issue. It's not specific to this graph, other examples have the same behavior. I'm not sure how to even troubleshoot this!

Answer 1

This solved my problem : Display plots in jupyter
Which points to : How to install properly altair in anaconda and enable ipyvega
Install altair :
conda install altair --channel conda-forge
Run this line in command line before launching jupyter :
jupyter nbextension enable vega --py --sys-prefix
Launch notebook :
jupyter notebook