[FIXED] How to plot a opaque pie chart on top of a Basemap background?

Issue

I would like to draw pie charts on a map using Basemap and plt.pie. What I want in the end, is that the pie charts are covering the overlapping country borders/coastlines. However, the resulting pie charts are transparent, i.e. I can still see the country borders/coastlines under the pie charts. Below is the resulting figure.

I thought it's due to the transparency of the pie chart, so I set wedgeprops={'alpha':1}, but the pie chart is still transparent.

Any ideas on what I should do? Thank you.

My code is given below:

import matplotlib.pyplot as plt
from mpl_toolkits.basemap import Basemap as Basemap

m = Basemap(
        projection='cyl', 
        llcrnrlon=-10,
        llcrnrlat=50,
        urcrnrlon=5,
        urcrnrlat=60,
        resolution='l')

m.drawcountries()
m.drawcoastlines()


attributes = [1,5,2]

a = plt.pie(
    attributes,
    center=(m(-2.78, 53.98)), 
    colors = ["tab:purple", "tab:blue", "tab:red"],
    # wedgeprops={'alpha':1},
    radius= 2)
    

axis = plt.gca()
axis.set_xlim([-10, 5]) 
axis.set_ylim([50, 60])

Solution

You need to set zorder properly.

m.drawcountries(zorder=-10)
m.drawcoastlines(zorder=-11)

This places the map's layers below the pie chart.

Answered By - swatchai