python中如何画对数函数图？

import math

import matplotlib.pyplot as plt

import numpy as np

"""简单log函数的实现"""

if __name__ == '__main__':

    x = np.arange(0.05,3,0.05)

    print(x)

    y1 = [math.log(a ,1.5) for a in x]

   plt.plot(x,y1,linewidth=2,color="#007500",label='log1.5(x)')

    plt.plot([1,1],[y1[0],y1[-1]],"r--",linewidth=2)

    y2 = [math.log(a, 2)for a in x]

    plt.plot(x, y2, linewidth=2, color="#9F35FF", label="log2(x)")

    y3 = [math.log(a, 3) for a in x]

    plt.plot(x, y3, linewidth=2, color="#F75000", label="log3(x)")

    plt.legend(loc="lower right")

    plt.grid(True)

    plt.show()