This question was asked under 'Python3.6' and you didn't say you require matplotlib, so here is one way with tkinter:
try:
from Tkinter import *
except:
from tkinter import *
root = Tk()
canvas = Canvas(root, width=500, height=300)
canvas.pack()
#center pie chart by using (150,50) as top left corner, (350, 250) as lower right
# square aspect because 350 - 150 = 250 - 50 = 200
# center is at (250, 150), radius is (350 - 150) / 2 = 100
startAngle = 45 # degrees
extentAngle = 90
# draw the wedge using Tkinter instead of MatPlotLib.
canvas.create_arc(150, 50, 350, 250, start=startAngle, extent=extentAngle, style=PIESLICE)
mainloop()