KNN不同邻居数可视化

def solve():
    import pandas as pd
    import matplotlib.pyplot as plt
    from sklearn.neighbors import KNeighborsRegressor
    from sklearn.model_selection import train_test_split
    df = pd.read_csv(____)
    X = df.drop(____); y = df["____"]
    X_train, X_test, y_train, y_test = train_test_split(____)
    ks = [____, ____, ____, ____, ____]
    r2s = []
    for k in ks:
        knn = KNeighborsRegressor(____).fit(____)
        r2s.append(knn.score(____))
    plt.plot(____); plt.xlabel(____); plt.ylabel(____)
    plt.title(____); plt.show()
    print("____".join(f"____" for k, r in zip(____)))