final i think

main.py

@@ -31,11 +31,12 @@ class TabletteChocolat:
         return TabletteChocolat(self.m - i, self.n - j)
 
     def plot(self):
+        plt.fill((0, self.n, self.n, 0, 0), (0, 0, self.m, self.m, 0), color='brown')
         for i in range(self.n):
             for j in range(self.m):
-                plt.plot((i, i+1, i+1, i, i), (j, j, j+1, j+1, j), color='black')
+                plt.plot((i+0.1, i+0.9, i+0.9, i+0.1, i+0.1), (j+0.1, j+0.1, j+0.9, j+0.9, j+0.1), color='black')
                 if i == self.n -1 and j == 0:
-                    plt.fill((i, i + 1, i + 1, i, i), (j, j, j + 1, j + 1, j), color='black')
+                    plt.fill((i+0.1, i+0.9, i+0.9, i+0.1, i+0.1), (j+0.1, j+0.1, j+0.9, j+0.9, j+0.1), color='black')
         plt.gca().set_aspect('equal')
         plt.axis('off')
         plt.show()