covid19-heatmap.py

#!/usr/bin/env python3

# Browse to this URL and click download link under heatmap:
# https://coronavirus.data.gov.uk/details/cases?areaType=nation&areaName=England

import json, datetime
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import matplotlib.colors as colors

with open ("data.json", "r") as fs:
    alldata = json.load(fs)

datablock = list(reversed(alldata["data"]))
caselist = [x["newCasesBySpecimenDateAgeDemographics"] for x in datablock]
dates = [x["date"] for x in datablock]
dateobj = [datetime.datetime.strptime(d,'%Y-%m-%d').date() for d in dates]

agelist = [x["age"] for x in caselist[0]]
removelist = ["00_59", "60+", "unassigned"]
agelist = [a for a in agelist if a not in removelist]
ageticks = [a.replace("_", "-") for a in agelist]

rollingsums = []
for daylist in caselist:
    daydict = []
    for agedict in daylist:
        if agedict["age"] in agelist:
            daily = agedict["rollingSum"] / 7.0
            daydict.append(daily)
    rollingsums.append(daydict)
rollingmap = list(zip(*rollingsums))

fig, ax = plt.subplots()
cmesh = ax.pcolormesh(dateobj, ageticks, rollingmap,
        cmap="gist_heat", norm=colors.PowerNorm(gamma=0.65),  shading='auto')

ax.xaxis.set_major_formatter(mdates.DateFormatter('%b %Y'))
ax.xaxis.set_major_locator(mdates.MonthLocator())
fig.autofmt_xdate()

cbar = fig.colorbar(cmesh, fraction=0.1)
cbar.cmap.set_gamma(0.5)

fig.set_size_inches(10, 5)
top = "ENGLAND - Covid 19 Heatmap - Total cases in each age range per day"
ax.set_title(top, fontsize=13)
fig.tight_layout()
fig.savefig("heatmap.png")
plt.show()