怎么使用Python绘制分段函数

import matplotlib.pyplot as pltimport numpy as npdef f(x):    if x <= -1:        return -0.5 - x    if -1 < x <= 1:        return 0.5 * (x ** 2)    else:        return x - 0.5x = np.linspace(-3, 3)y = []for i in x:    y_1 = f(i)    y.append(y_1)plt.plot(x, y)plt.grid()plt.show()

import matplotlib.pyplot as pltimport numpy as npdef f(x):    if x <= -1:        return 1    if -1 < x <= 1:        return 0.5 * (x ** 2)    else:        return 1x = np.linspace(-3, 3)y = []for i in x:    y_1 = f(i)    y.append(y_1)y_2 = x ** 2plt.plot(x, y)plt.grid()plt.show()