指数平滑预测

def solve():
    import pandas as pd
    import matplotlib.pyplot as plt
    url = '____'
    df = pd.read_csv(____).sort_values(____)
    alpha = ____
    smoothed = [df['____'].iloc[____]]
    for v in df['____'].iloc[____:]:
        smoothed.append(alpha*v + (____-alpha)*smoothed[-____])
    df['____'] = smoothed
    print(df[['____','____','____']].tail(____).to_string(____))
    print(____)
    plt.plot(____)
    plt.plot(____)
    plt.xlabel(____); plt.ylabel(____); plt.title(____); plt.legend()
    plt.tight_layout(); plt.show()