删除缺失率超过30%的字段

def solve():
    from pyodide.http import open_url
    from io import StringIO
    loans_raw_csv = open_url("https://data.zuihe.com/dbd/riskctrl/state_02/loans_raw.csv").read()
    loans_clean_csv = open_url("https://data.zuihe.com/dbd/riskctrl/state_02/loans_clean.csv").read()
    import pandas as pd
    from io import StringIO
    df = pd.read_csv(StringIO(loans_raw_csv))
    high_miss = df.columns[df.isnull().mean()>0.3].tolist()
    print(f"缺失率>30%的列: {high_miss}")
    df2 = df.drop(columns=high_miss)
    print(f"删除后列数: {df2.shape[1]}（原{df.shape[1]}列）")