Python 我不能用ffmpeg保存动画

我试过各种各样的例子，虽然我找不到合适的解决办法。这是我的项目的示例代码，我想将其保存为mp4格式，并使用ffmpeg。如果我使用df=pd.DataFrame（np.random.rand（250,3）），动画就被保存了，但是它对我的示例代码不起作用，它显示了key error=0。注：df1=pd.DataFrame（np.random.randint（5,15，[250,3]）。 如对此有任何建议，将不胜感激。先谢谢你

import pandas as pd
import numpy as np
import ma``tplotlib.pyplot as plt
import matplotlib.animation as animation

df = data.iloc[0:250, 4:12]
df1 = df2.iloc[:,0:3]

a1 = df.iloc[:,0]/2
a2 = df.iloc[:,1]/2
b1 = df.iloc[:,2]/2
b2 = df.iloc[:,3]/2
c1 = df.iloc[:,4]/2
c2 = df.iloc[:,5]/2
m1 = df1.iloc[:,0]
m2 = df1.iloc[:,1]
m3 = df1.iloc[:,2]

fig ,ax = plt.subplots()

l1, = ax.plot (vert1, vert2, 'ro', markersize = m1[0])
l2, = ax.plot (long1, long2, 'ro', markersize = m2[0])
l3, = ax.plot (tras1, tras2, 'ro', markersize = m3[0])

def init():    
    l1.set_data([],[])
    l2.set_data([],[])
    l3.set_data([],[])
    
    return (l1,l2,l3)

def animate(i,l1,l2,l3):
    
    l1.set_data(vert1[i], vert2[i])
    l1.set_markersize(m1[i])
    l2.set_data(long1[i], long2[i])
    l2.set_markersize(m2[i])
    l3.set_data(tras1[i], tras2[i])
    l3.set_markersize(m3[i])

    return (l1,l2,l3)

Writer = animation.writers['ffmpeg']
writer = Writer(fps= 100, metadata = dict(artist = 'me'), bitrate = 1800)

ani = animation.FuncAnimation(fig, animate, fargs=(l1,l2,l3), init_func=init, interval=10, blit=False)
ani.save('/Users/gokulthangavel/Downloads/basic_animation.mp4', writer = writer)

plt.show()