对违约样本进行欠采样至1:3

def solve():
    from pyodide.http import open_url
    from io import StringIO
    loans_raw_csv = open_url(____).read()
    loans_clean_csv = open_url(____).read()
    import pandas as pd
    from io import StringIO
    df = pd.read_csv(StringIO(____))
    bad=df[df['____']==____]; good=df[df['____']==____]
    print(____)
    good_sample=good.sample(n=min(len(____)*____,len(____)),random_state=____)
    df2=pd.concat(____).reset_index(____)
    print(____)