完整数据清洗流程

def solve():
    import pandas as pd
    import numpy as np
    df = pd.read_csv(____)
    df['____'] = df['____'].fillna(df['____'].mean())
    df['____'] = df['____'].fillna(df['____'].mode()[____])
    df['____'] = df['____'].astype(____)
    df['____'] = df['____'].astype(____)
    report = {
        '____': len(____),
        '____': int(df.isnull().sum().sum()),
        '____': round(float(df['____'].mean()), ____)
    }
    print(____)