如何使用4个图例而不是2个图例来更改python pyplot图例

import matplotlib.pyplot as plt

fig, ax = plt.subplots()

line1, = ax.plot(x1, y1, label='Line 1')
line2, = ax.plot(x2, y2, label='Line 2')
line3, = ax.plot(x3, y3, label='Line 3')
line4, = ax.plot(x4, y4, label='Line 4')

ax.legend(handles=[line1, line2, line3, line4])

import matplotlib.pyplot as plt

fig, ax = plt.subplots()

line1, = ax.plot(x1, y1, label='Line 1')
line2, = ax.plot(x2, y2, label='Line 2')
line3, = ax.plot(x3, y3, label='Line 3')
line4, = ax.plot(x4, y4, label='Line 4')

ax.legend(handles=[line1, line2, line3, line4])

plt.show()