Add edges in the pie chart exercise

Edges can be specified with a dictionary of arguments passed to the
wedgeprops keyword.

Author: jruota

scripts/pie_ex.py

@@ -9,9 +9,10 @@
 Z = np.ones(n)
 Z[-1] *= 2
 
-plt.axes([0.025,0.025,0.95,0.95])
+plt.axes([0.025, 0.025, 0.95, 0.95])
 
-plt.pie(Z, explode=Z*.05, colors = ['%f' % (i/float(n)) for i in range(n)])
+plt.pie(Z, explode=Z*.05, colors=['%f' % (i/float(n)) for i in range(n)],
+        wedgeprops={"linewidth": 1, "edgecolor": "black"})
 plt.gca().set_aspect('equal')
 plt.xticks([]), plt.yticks([])