rmse_desc = [0.31703, 0.31701, 0.31707, 0.317, 0.31713, 0.31698, 0.31697, 
    0.31688, 0.31697, 0.31699]
order = np.argsort(desc_x)
xs = np.array(desc_x)[order]
ys = np.array(rmse_desc)[order]
fig = plt.figure()
ax = plt.subplot(111)
fig.suptitle('title')
plt.xlabel('x')
plt.ylabel('y')
ax.plot(xs, ys, 'b', label='desc')
ax.legend()
plt.show()
Intersecting matplotlib graph with unsorted data