Folium heatmap not displaying

I have an output file data.json

 [{"5403": 2, "9734": 1, "2565": 5, "5087": 2, "9061": 1, "1761": 4, "4811": 7 "1111": 5, "3891": 3, "1962": 3}]

and a shapefile converted to geojson https://www.dropbox.com/s/uou0jxhpklgt8r6/pc4.json?dl=0

I use this code to generate the map in ipython notebook:

import folium
import numpy as np
from IPython.display import IFrame
from IPython.core.display import HTML

def inline_map(m, width=650, height=500):
    """Takes a folium instance and embed HTML."""
    m._build_map()
    srcdoc = m.HTML.replace('"', '"')
    embed = HTML('<iframe srcdoc="{}" '
                 'style="width: {}px; height: {}px; '
                 'border: none"></iframe>'.format(srcdoc, width, height))
    return embed

    mapa = folium.Map(width=900, height=600, zoom_start=7, location=[52.3, 5], tiles='Mapbox Bright')

mapa.geo_json(geo_path='pc4.json', 
              data_out='data.json', 
              data=pcs, 
              columns=["PC4","Count"], 
              key_on="feature.properties.PC4",
              fill_color='PuRd',
              fill_opacity=1, 
              line_opacity=1,
              legend_name='Demand',
              reset="True")

mapa.create_map('test.html')
IFrame('test.html', width=1000, height=700)

It creates the map fine, just as the output file, but it doesn’t overlay any heatmap. It does show the legend though, but nothing else.

I know this question is similar to Geopandas/folium map not displaying but his solution doesn’t do anything for me.