如果这是您的意思，您可以在同一个图中绘制多条线，如下所示：

import matplotlib.pyplot as plt

x = [0, 1, 2, 4, 6, 9, 10, 15]
y1 = [0, 1, 4, 16, 25, 16, 45, 18]
y2 = [6, 5, 4, 2, 3, 1, 4, 3]

plt.xlim([2, 9])

plt.plot(x, y1)
plt.plot(x, y2)

plt.show()

此外，要获得最高点：

import numpy as np

x = [0, 1, 2, 4, 6, 9, 10, 15]
y1 = [0, 1, 4, 16, 25, 16, 45, 18]
y2 = [6, 5, 4, 2, 3, 1, 4, 3]

y1 = [y1[i] for i in range(len(x)) if 2 <= x[i] <= 9]
y2 = [y2[i] for i in range(len(x)) if 2 <= x[i] <= 9]
x = [i for i in x if 2 <= i < 9]

print("y1 max:", np.amax(y1))
print("y2 max:", np.amax(y2))