模型选择-网格搜索

def solve():
    import pandas as pd
    from sklearn.neighbors import KNeighborsClassifier
    from sklearn.model_selection import GridSearchCV
    df = pd.read_csv(____)
    X = df.drop(____)
    y = df['____']
    knn = KNeighborsClassifier()
    param_grid = {'____': [____, ____, ____, ____]}
    grid = GridSearchCV(____)
    grid.fit(____)
    print(____)
    print('____', round(____))