绘制ACF自相关函数图

import pandas as pd
import matplotlib
matplotlib.use(____)
import matplotlib.pyplot as plt
from statsmodels.graphics.tsaplots import plot_acf
from statsmodels.tsa.stattools import acf

def solve():
    url = '____'
    df = pd.read_excel(____)
    fig, ax = plt.subplots(figsize=(____, ____))
    plot_acf(____)
    plt.title(____)
    plt.tight_layout()
    plt.show()
    acf_vals = acf(____)
    print(____)