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pythonfoliumaltairvega-lite

Unable to insert altair visualisation as popup in folium map

I'm relatively new to python and this is the first project that I'm working on. I'm trying to plot a simple multi line chart using altair onto a folium marker's popup. I followed the examples on this page https://github.com/python-visualization/folium/blob/master/examples/Popups.ipynb. But when I click on the marker, it's just plain white. The map and markers are plotted fine except the popup. This is what my whole dataset looks like :

enter image description here

Here is the code:

import pandas as pd
import folium
import altair as alt
import json

chart = alt.Chart(df).mark_line().encode(
        x='index',
        y='Ambala',
        color='Variable')

chart_2 = json.loads(chart.to_json())
m = folium.Map([30,-80],zoom_start=2)
popup = folium.Popup(max_width=650)
folium.Vega(chart_2, height=350, width=650).add_to(popup)
folium.Marker([30, -80], popup=popup).add_to(m)
m

Note that this just a sample of code. I'll be implementing this on a larger scale in my project. I tried to plot a visualization (which I found here : https://github.com/python-visualization/folium/blob/master/examples/data/vis1.json) and this seemed to work fine. I just don't understand why the same code works for their plot but not for mine even though altair produces a fine looking chart from my code. Sorry if this is sounds silly, I'm still a beginner and python is my first language. Thanks

Solution

  • If you want to use an Altair chart inside a folium map, you need to use a VegaLite object instead of a Vega object. You just need to change the line with the Vega object like that : folium.features.VegaLite(chart_2, height=350, width=650).add_to(popup)folium map