Apply suggestions from code review

Co-authored-by: Hugo <hugo.talbot@sofa-framework.org>

Author: alxbilger

examples/access_mass_matrix.py

@@ -55,5 +55,5 @@ def onAnimateEndEvent(self, event):
             np.savetxt('mass.csv', mass_matrix.toarray(), delimiter=',')
         if showImage:
             plt.imshow(mass_matrix.toarray(), interpolation='nearest', cmap='gist_gray')
-            plt.show()
+            plt.show(block=False)
 

examples/access_stiffness_matrix.py

@@ -55,5 +55,5 @@ def onAnimateEndEvent(self, event):
             np.savetxt('stiffness.csv', stiffness_matrix.toarray(), delimiter=',')
         if showImage:
             plt.imshow(stiffness_matrix.toarray(), interpolation='nearest', cmap='gist_gray')
-            plt.show()
+            plt.show(block=False)